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5,018 results on '"Shen F."'

1. Manifestation of solar wind corotating interaction regions in GCR intensity variations

Author

Krainev M. B., Kalinin M. S., Bazilevskaya G. A., Svirzhevskaya A. K., Svirzhevsky N. S., Luo X., Aslam O., Shen F., Ngobeni M., and Potgieter M.

Subjects
heliosphere, corotating interaction regions, galactic cosmic rays, gcr modulation, long-term gcr variations, 27-day gcr intensity variation, mhd approximation, monte carlo method, Astrophysics, QB460-466
Abstract

The regions of interaction between solar wind streams of different speed, known as corotating interaction regions, form an almost constantly existing structure of the inner heliosphere. Using observational data on the main characteristics of the heliosphere, important for GCR modulation, and the results of 3D MHD modeling of corotating interaction regions, and Monte Carlo simulation of recurrent GCR variations, we analyze the importance of the corotating interaction regions for longitude-averaged characteristics of the heliosphere and GCR propagation, and possible ways for simulating long-term GCR intensity variations with respect to the corotating interaction regions.

Published
2023
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2. The melting performance blast furnace slags with high alumina content

Author

Zheng H.-Y., Zhang Y., Wang Z., Du J.-L., Jiang X., Gao Q.-J., and Shen F.-M.

Subjects
high alumina blast furnace slag, melting characteristic temperature, melting heat, differential scanning calorimetry, raman spectrum analysis, Mining engineering. Metallurgy, TN1-997
Abstract

With a view to understanding the performance of the blast furnace slag with high Al2O3 content, the effects of w(MgO)/w(Al2O3), w(CaO)/w(SiO2), and w(Al2O3) on the melting performance (melting characteristic temperature and melting heat) of the blast furnace slag with high Al2O3 content were investigated by the differential scanning calorimeter (DSC) method. Experimental results indicate that melting end temperature (Tend) for almost all the slags has no obvious change with the increase of w(MgO)/w(Al2O3), w(CaO)/w(SiO2) and w(Al2O3) of the slag will raise Tend of the slag. When (w(MgO)/w(Al2O3), R, and w(Al2O3) are high, the melting onset temperature (Tonset) of the slag increases with the increase of any variables. When w(CaO)/w(SiO2) is low, Tonset of the slag decreases with the increase of w(Al2O3). w(MgO)/w(Al2O3), w(CaO)/w(SiO2), and w(Al2O3) within the scope of this study and all these factors lead to the increase of the slag melting heat.

Published
2023
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3. Influence of iron ore concentrate on the characteristics of sintering and reduction of sinter

Author

Guo H., Shen F.-M., Jiang X., Xiang D.-W., and Zheng H.-Y.

Subjects
iron ore, fluidity mechanism of ore, reduction, model function, Mining engineering. Metallurgy, TN1-997
Abstract

As Australia is the main iron ore importing country for China, the abundant mineral resources of Australia are the primary raw materials for the sintering process. To better understand the properties of different iron ores from Australia and then guide the sintering process, this study selected four types of Australian ore and one type of domestic ore, and their properties were investigated under different conditions. The experiment of single iron ore sintering was studied to examine the influence of different iron ores on the metallurgical properties of sinter. From this study, the following results were obtained: GG showed poor fluidity and higher assimilability temperature, but the bonding phase strength was the highest; YD showed better fluidity and lower assimilability temperature, whereas SJY (domestic ore) showed better fluidity and higher bonding phase strength, and lower assimilability temperature. The influence mechanism of iron ore on the fluidity was further analyzed by using SEM and ion theory of slag. With the increase SiO2 content of iron ore, the fluidity index increased, the main reason was that the amount of liquid phase increased and the melting point decreased during the sintering. However, an excessive amount of SiO2 caused the decrease of fluidity index of iron ore; the main reason was that the fluidity of the liquid phase itself decreased and secondary hematite appeared. In the case of the higher SiO2 content of iron ore, the main bonding phase was calcium silicate. With the decrease of SiO2 content, the calcium silicate transformed into calcium ferrite. The main reason for this was that the Gibbs free energy of calcium ferrite and dicalcium ferrite (2CaO·SiO2) was higher than that of calcium silicate in the temperature ranges of 400-1600 K. The reduction degree of YD was the highest in all the cases and that of GG was the lowest. Activation energies of 5.39, 3.14, 3.51, 4.47 and 2.92 kJ/mol were obtained for the reduction of GG, PB, BH, SJY, and YD, respectively. In all the cases, the reaction corresponded to the model function of F1(α), and the integral form was -ln(1-α)=kt. Through this investigation, it could be concluded that the most appropriate ore category for sinter pot was YD.

Published
2020
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4. Protective mechanism of unburned pulverized coal to coke in blast furnace

Author

Xiang D.-W., Shen F.-M., Jiang X., Yang J.-L., Li X.-J., and Gao Q.-J.

Subjects
unburned pulverized coal, coke reactivity, coke strength after reaction, apparent porosity, the synthetic weighted mark method, Mining engineering. Metallurgy, TN1-997
Abstract

The edge and internal morphology of coke with different contents of UPC (unburned pulverized coal) after reaction with CO2 were analyzed by SEM. The influence of UPC on CRI (coke reactivity)，CSR (coke strength after reaction) and apparent porosity was also studied. The synthetic weighted mark method was used to analyze the comprehensive effect of UPC content on coke quality. The results show that because of the decrease of the content of intermediates Cf(O) and C(O)Cf(O) the restrictive step between the coke and CO2 is an interfacial chemical reaction, and it accords with the Mckewan equation 1-(1-α)1/3=kt. The UPC has a strong effect on coke when the content of UPC is 10~20%; meanwhile , the CRI and the apparent porosity are significantly decreased by 6.8% and 9.5%, respectively, and the CSR is significantly increased by 3.8%. The UPC can effectively reduce the effect of CO2 on the edge and the internal erosion of coke; the large pores and the pulverization of coke were avoided. The results of the synthetic weighted mark method showed that the comprehensive quality of coke changed greatly when the content of unburned pulverized coal was 11.24~20.87%, which is in agreement with the experimental results.

Published
2019
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7. Preparing Li-garnet electrodes with engineered structures by phase inversion and high shear compaction processes

Author

Shen, F, Jonson, RA, Parkinson, DY, and Tucker, MC

Subjects
garnet, infiltration, LLZO, porous scaffold, solid-state battery, Materials, Materials Engineering, Mechanical Engineering
Abstract

Solid-state lithium batteries are promising for safety and energy density compared with traditional lithium-ion batteries. However, the large interfacial resistance between the electrode and electrolyte is a bottleneck to achieving high-performance solid-state batteries. Engineered electrode structures with a porous scaffold of the solid electrolyte material are promising to lower the interfacial resistance and provide a mechanical support for a thin solid electrolyte layer. In this work, two ceramic processing techniques are used to fabricate porous/dense bilayer architectures based on a Li6.25Al0.25La3Zr2O12 (LLZO) Li-garnet material. Finger-like vertically aligned pores are created by the phase inversion (PI) process. A water bath presaturated with Li salt prevents Li loss during the PI solvent exchange step. Pore size and porosity can be optimized by adjusting the bath temperature. The high shear compaction process was used to prepare LLZO tapes with 40, 60, and 80 vol% poreformer. The porosity of the tapes after sintering is 39.5%, 58.4%, and 75.4%, respectively. Microtomography exhibits the porosity, pore shape, and pore distribution of the tapes. A typical cathode material LiNi0.33Mn0.33Co0.33O2 (NMC) is filled into the pores via vacuum infiltration, and a dense cathode layer is formed within the garnet scaffold.

Published
2022

9. Flow and interferometry results from Au+Au collisions at $\sqrt{\textit{s}_{NN}}$ = 4.5 GeV

Author

STAR Collaboration, Adam, J., Adamczyk, L., Adams, J. R., Adkins, J. K., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alekseev, I., Anderson, D. M., Aparin, A., Aschenauer, E. C., Ashraf, M. U., Atetalla, F. G., Attri, A., Averichev, G. S., Bairathi, V., Barish, K., Behera, A., Bellwied, R., Bhasin, A., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Brandenburg, J. D., Brandin, A. V., Butterworth, J., Caines, H., Sánchez, M. Calderón de la Barca, Campbell, J. M., Cebra, D., Chakaberia, I., Chaloupka, P., Chan, B. K., Chang, F-H., Chang, Z., Chankova-Bunzarova, N., Chatterjee, A., Chen, D., Chen, J. H., Chen, X., Chen, Z., Cheng, J., Cherney, M., Chevalier, M., Choudhury, S., Christie, W., Chu, X., Crawford, H. J., Csanád, M., Daugherity, M., Dedovich, T. G., Deppner, I. M., Derevschikov, A. A., Didenko, L., Dong, X., Drachenberg, J. L., Dunlop, J. C., Edmonds, T., Elsey, N., Engelage, J., Eppley, G., Esha, R., Esumi, S., Evdokimov, O., Ewigleben, A., Eyser, O., Fatemi, R., Fazio, S., Federic, P., Fedorisin, J., Feng, C. J., Feng, Y., Filip, P., Finch, E., Fisyak, Y., Francisco, A., Fulek, L., Gagliardi, C. A., Galatyuk, T., Geurts, F., Gibson, A., Gopal, K., Grosnick, D., Guryn, W., Hamad, A. I., Hamed, A., Harabasz, S., Harris, J. W., He, S., He, W., He, X. H., Heppelmann, S., Herrmann, N., Hoffman, E., Holub, L., Hong, Y., Horvat, S., Hu, Y., Huang, H. Z., Huang, S. L., Huang, T., Huang, X., Humanic, T. J., Huo, P., Igo, G., Isenhower, D., Jacobs, W. W., Jena, C., Jentsch, A., JI, Y., Jia, J., Jiang, K., Jowzaee, S., Ju, X., Judd, E. G., Kabana, S., Kabir, M. L., Kagamaster, S., Kalinkin, D., Kang, K., Kapukchyan, D., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kelsey, M., Khyzhniak, Y. V., Kikoła, D. P., Kim, C., Kimelman, B., Kincses, D., Kinghorn, T. A., Kisel, I., Kiselev, A., Kocan, M., Kochenda, L., Kosarzewski, L. K., Kozyra, L., Kramarik, L., Kravtsov, P., Krueger, K., Mudiyanselage, N. Kulathunga, Kumar, L., Elayavalli, R. Kunnawalkam, Kwasizur, J. H., Lacey, R., Lan, S., Landgraf, J. M., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Leung, Y. H., Li, C., Li, W., Li, X., Li, Y., Liang, Y., Licenik, R., Lin, T., Lin, Y., Lisa, M. A., Liu, F., Liu, H., Liu, P., Liu, T., Liu, X., Liu, Y., Liu, Z., Ljubicic, T., Llope, W. J., Longacre, R. S., Lukow, N. S., Luo, S., Luo, X., Ma, G. L., Ma, L., Ma, R., Ma, Y. G., Magdy, N., Majka, R., Mallick, D., Margetis, S., Markert, C., Matis, H. S., Mazer, J. A., Meehan, K., Minaev, N. G., Mioduszewski, S., Mohanty, B., Mondal, M. M., Mooney, I., Moravcova, Z., Morozov, D. A., Nagy, M., Nam, J. D., Nasim, Md., Nayak, K., Neff, D., Nelson, J. M., Nemes, D. B., Nie, M., Nigmatkulov, G., Niida, T., Nogach, L. V., Nonaka, T., Nunes, A. S., Odyniec, G., Ogawa, A., Oh, S., Okorokov, V. A., Page, B. S., Pak, R., Pandav, A., Panebratsev, Y., Pawlik, B., Pawlowska, D., Pei, H., Perkins, C., Pinsky, L., Pintér, R. L., Pluta, J., Porter, J., Posik, M., Pruthi, N. K., Przybycien, M., Putschke, J., Qiu, H., Quintero, A., Radhakrishnan, S. K., Ramachandran, S., Ray, R. L., Reed, R., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ruan, L., Rusnak, J., Sahoo, N. R., Sako, H., Salur, S., Sandweiss, J., Sato, S., Schmidke, W. B., Schmitz, N., Schweid, B. R., Seck, F., Seger, J., Sergeeva, M., Seto, R., Seyboth, P., Shah, N., Shahaliev, E., Shanmuganathan, P. V., Shao, M., Shen, F., Shen, W. Q., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Sikora, R., Simko, M., Singh, J., Singha, S., Smirnov, N., Solyst, W., Sorensen, P., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Stefaniak, M., Stewart, D. J., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Sumbera, M., Summa, B., Sun, X. M., Sun, X., Sun, Y., Surrow, B., Svirida, D. N., Szymanski, P., Tang, A. H., Tang, Z., Taranenko, A., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Tlusty, D., Tokarev, M., Tomkiel, C. A., Trentalange, S., Tribble, R. E., Tribedy, P., Tripathy, S. K., Tsai, O. D., Tu, Z., Ullrich, T., Underwood, D. G., Upsal, I., Van Buren, G., Vanek, J., Vasiliev, A. N., Vassiliev, I., Videbæk, F., Vokal, S., Voloshin, S. A., Wang, F., Wang, G., Wang, J. S., Wang, P., Wang, Y., Wang, Z., Webb, J. C., Weidenkaff, P. C., Wen, L., Westfall, G. D., Wieman, H., Wissink, S. W., Witt, R., Wu, Y., Xiao, Z. G., Xie, G., Xie, W., Xu, H., Xu, N., Xu, Q. H., Xu, Y. F., Xu, Y., Xu, Z., Yang, C., Yang, Q., Yang, S., Yang, Y., Yang, Z., Ye, Z., Yi, L., Yip, K., Zbroszczyk, H., Zha, W., Zhang, C., Zhang, D., Zhang, S., Zhang, X. P., Zhang, Y., Zhang, Z. J., Zhang, Z., Zhao, J., Zhong, C., Zhou, C., Zhu, X., Zhu, Z., Zurek, M., and Zyzak, M.

Subjects
Nuclear Experiment
Abstract

The Beam Energy Scan (BES) program at the Relativistic Heavy Ion Collider (RHIC) was extended to energies below $\sqrt{\textit{s}_{NN}}$ = 7.7 GeV in 2015 by successful implementation of the fixed-target mode of operation in the STAR (Solenoidal Track At RHIC) experiment. In the fixed-target mode, ions circulate in one ring of the collider and interact with a stationary target at the entrance of the STAR Time Projection Chamber. The first results for Au+Au collisions at $\sqrt{\textit{s}_{NN}}$ = 4.5 GeV are presented, including directed and elliptic flow of identified hadrons, and radii from pion femtoscopy. The proton flow and pion femtoscopy results agree quantitatively with earlier measurements by Alternating Gradient Synchrotron experiments at similar energies. This validates running the STAR experiment in the fixed-target configuration. Pion directed and elliptic flow are presented for the first time at this beam energy. Pion and proton elliptic flow show behavior which hints at constituent quark scaling, but large error bars preclude reliable conclusions. The ongoing second phase of BES (BES-II) will provide fixed-target data sets with 100 times more events at each of several energies down to $\sqrt{\textit{s}_{NN}}$ = 3.0 GeV., Comment: 18 pages, 20 figures; Contexts and figure caption was modified, one reference was added to address the referee's comments

Published
2020
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10. Beam-Energy Dependence of the Directed Flow of Deuterons in Au+Au Collisions

Author

STAR Collaboration, Adam, J., Adamczyk, L., Adams, J. R., Adkins, J. K., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alekseev, I., Anderson, D. M., Aparin, A., Aschenauer, E. C., Ashraf, M. U., Atetalla, F. G., Attri, A., Averichev, G. S., Bairathi, V., Barish, K., Behera, A., Bellwied, R., Bhasin, A., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Brandenburg, J. D., Brandin, A. V., Butterworth, J., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Chakaberia, I., Chaloupka, P., Chan, B. K., Chang, F-H., Chang, Z., Chankova-Bunzarova, N., Chatterjee, A., Chen, D., Chen, J. H., Chen, X., Chen, Z., Cheng, J., Cherney, M., Chevalier, M., Choudhury, S., Christie, W., Chu, X., Crawford, H. J., Csanád, M., Daugherity, M., Dedovich, T. G., Deppner, I. M., Derevschikov, A. A., Didenko, L., Dong, X., Drachenberg, J. L., Dunlop, J. C., Edmonds, T., Elsey, N., Engelage, J., Eppley, G., Esumi, S., Evdokimov, O., Ewigleben, A., Eyser, O., Fatemi, R., Fazio, S., Federic, P., Fedorisin, J., Feng, C. J., Feng, Y., Filip, P., Finch, E., Fisyak, Y., Francisco, A., Fulek, L., Gagliardi, C. A., Galatyuk, T., Geurts, F., Gibson, A., Gopal, K., Grosnick, D., Guryn, W., Hamad, A. I., Hamed, A., Harabasz, S., Harris, J. W., He, S., He, W., He, X. H., Heppelmann, S., Herrmann, N., Hoffman, E., Holub, L., Hong, Y., Horvat, S., Hu, Y., Huang, H. Z., Huang, S. L., Huang, T., Huang, X., Humanic, T. J., Huo, P., Igo, G., Isenhower, D., Jacobs, W. W., Jena, C., Jentsch, A., JI, Y., Jia, J., Jiang, K., Jowzaee, S., Ju, X., Judd, E. G., Kabana, S., Kabir, M. L., Kagamaster, S., Kalinkin, D., Kang, K., Kapukchyan, D., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kelsey, M., Khyzhniak, Y. V., Kikoła, D. P., Kim, C., Kimelman, B., Kincses, D., Kinghorn, T. A., Kisel, I., Kiselev, A., Kocan, M., Kochenda, L., Kosarzewski, L. K., Kramarik, L., Kravtsov, P., Krueger, K., Mudiyanselage, N. Kulathunga, Kumar, L., Kumar, S., Elayavalli, R. Kunnawalkam, Kwasizur, J. H., Lacey, R., Lan, S., Landgraf, J. M., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Leung, Y. H., Li, C., Li, W., Li, X., Li, Y., Liang, Y., Licenik, R., Lin, T., Lin, Y., Lisa, M. A., Liu, F., Liu, H., Liu, P., Liu, T., Liu, X., Liu, Y., Liu, Z., Ljubicic, T., Llope, W. J., Longacre, R. S., Lukow, N. S., Luo, S., Luo, X., Ma, G. L., Ma, L., Ma, R., Ma, Y. G., Magdy, N., Majka, R., Mallick, D., Margetis, S., Markert, C., Matis, H. S., Mazer, J. A., Minaev, N. G., Mioduszewski, S., Mohanty, B., Mooney, I., Moravcova, Z., Morozov, D. A., Nagy, M., Nam, J. D., Nasim, Md., Nayak, K., Neff, D., Nelson, J. M., Nemes, D. B., Nie, M., Nigmatkulov, G., Niida, T., Nogach, L. V., Nonaka, T., Nunes, A. S., Odyniec, G., Ogawa, A., Oh, S., Okorokov, V. A., Page, B. S., Pak, R., Pandav, A., Panebratsev, Y., Pawlik, B., Pawlowska, D., Pei, H., Perkins, C., Pinsky, L., Pintér, R. L., Pluta, J., Porter, J., Posik, M., Pruthi, N. K., Przybycien, M., Putschke, J., Qiu, H., Quintero, A., Radhakrishnan, S. K., Ramachandran, S., Ray, R. L., Reed, R., Ritter, H. G., Rogachevskiy, O. V., Romero, J. L., Ruan, L., Rusnak, J., Sahoo, N. R., Sako, H., Salur, S., Sandweiss, J., Sato, S., Schmidke, W. B., Schmitz, N., Schweid, B. R., Seck, F., Seger, J., Sergeeva, M., Seto, R., Seyboth, P., Shah, N., Shahaliev, E., Shanmuganathan, P. V., Shao, M., Sheikh, A. I., Shen, F., Shen, W. Q., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Sikora, R., Simko, M., Singh, J., Singha, S., Smirnov, N., Solyst, W., Sorensen, P., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Stefaniak, M., Stewart, D. J., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Sumbera, M., Summa, B., Sun, X. M., Sun, X., Sun, Y., Surrow, B., Svirida, D. N., Szymanski, P., Tang, A. H., Tang, Z., Taranenko, A., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Tlusty, D., Tokarev, M., Tomkiel, C. A., Trentalange, S., Tribble, R. E., Tribedy, P., Tripathy, S. K., Tsai, O. D., Tu, Z., Ullrich, T., Underwood, D. G., Upsal, I., Van Buren, G., Vanek, J., Vasiliev, A. N., Vassiliev, I., Videbæk, F., Vokal, S., Voloshin, S. A., Wang, F., Wang, G., Wang, J. S., Wang, P., Wang, Y., Wang, Z., Webb, J. C., Weidenkaff, P. C., Wen, L., Westfall, G. D., Wieman, H., Wissink, S. W., Witt, R., Wu, Y., Xiao, Z. G., Xie, G., Xie, W., Xu, H., Xu, N., Xu, Q. H., Xu, Y. F., Xu, Y., Xu, Z., Yang, C., Yang, Q., Yang, S., Yang, Y., Yang, Z., Ye, Z., Yi, L., Yip, K., Zbroszczyk, H., Zha, W., Zhang, C., Zhang, D., Zhang, S., Zhang, X. P., Zhang, Y., Zhang, Z. J., Zhang, Z., Zhao, J., Zhong, C., Zhou, C., Zhu, X., Zhu, Z., Zurek, M., and Zyzak, M.

Subjects
Nuclear Experiment
Abstract

We present a measurement of the first-order azimuthal anisotropy, $v_1(y)$, of deuterons from Au+Au collisions at $\sqrt{s_{NN}}$ = 7.7, 11.5, 14.5, 19.6, 27, and 39 GeV recorded with the STAR experiment at the Relativistic Heavy Ion Collider (RHIC). The energy dependence of the $v_1(y)$ slope, $dv_{1}/dy|_{y=0}$, for deuterons, where $y$ is the rapidity, is extracted for semi-central collisions (10-40\% centrality) and compared to that of protons. While the $v_1(y)$ slopes of protons are generally negative for $\sqrt{s_{NN}} >$ 10 GeV, those for deuterons are consistent with zero, a strong enhancement of the $v_1(y)$ slope of deuterons is seen at the lowest collision energy (the largest baryon density) at $\sqrt{s_{NN}} =$ 7.7 GeV. In addition, we report the transverse momentum dependence of $v_1$ for protons and deuterons. The experimental results are compared with transport and coalescence models.

Published
2020
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11. Measurement of inclusive J/$\psi$ polarization in p+p collisions at $\sqrt{s}$ = 200 GeV by the STAR experiment

Author

STAR Collaboration, Adam, J., Adamczyk, L., Adams, J. R., Adkins, J. K., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alekseev, I., Anderson, D. M., Aparin, A., Aschenauer, E. C., Ashraf, M. U., Atetalla, F. G., Attri, A., Averichev, G. S., Bairathi, V., Barish, K., Behera, A., Bellwied, R., Bhasin, A., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Brandenburg, J. D., Brandin, A. V., Butterworth, J., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Chakaberia, I., Chaloupka, P., Chan, B. K., Chang, F-H., Chang, Z., Chankova-Bunzarova, N., Chatterjee, A., Chen, D., Chen, J. H., Chen, X., Chen, Z., Cheng, J., Cherney, M., Chevalier, M., Choudhury, S., Christie, W., Chu, X., Crawford, H. J., Csanád, M., Daugherity, M., Dedovich, T. G., Deppner, I. M., Derevschikov, A. A., Didenko, L., Dong, X., Drachenberg, J. L., Dunlop, J. C., Edmonds, T., Elsey, N., Engelage, J., Eppley, G., Esha, R., Esumi, S., Evdokimov, O., Ewigleben, A., Eyser, O., Fatemi, R., Fazio, S., Federic, P., Fedorisin, J., Feng, C. J., Feng, Y., Filip, P., Finch, E., Fisyak, Y., Francisco, A., Fulek, L., Gagliardi, C. A., Galatyuk, T., Geurts, F., Gibson, A., Gopal, K., Grosnick, D., Guryn, W., Hamad, A. I., Hamed, A., Harabasz, S., Harris, J. W., He, S., He, W., He, X. H., Heppelmann, S., Herrmann, N., Hoffman, E., Holub, L., Hong, Y., Horvat, S., Hu, Y., Huang, H. Z., Huang, S. L., Huang, T., Huang, X., Humanic, T. J., Huo, P., Igo, G., Isenhower, D., Jacobs, W. W., Jena, C., Jentsch, A., JI, Y., Jia, J., Jiang, K., Jowzaee, S., Ju, X., Judd, E. G., Kabana, S., Kabir, M. L., Kagamaster, S., Kalinkin, D., Kang, K., Kapukchyan, D., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kelsey, M., Khyzhniak, Y. V., Kikoła, D. P., Kim, C., Kimelman, B., Kincses, D., Kinghorn, T. A., Kisel, I., Kiselev, A., Kocan, M., Kochenda, L., Kosarzewski, L. K., Kramarik, L., Kravtsov, P., Krueger, K., Mudiyanselage, N. Kulathunga, Kumar, L., Elayavalli, R. Kunnawalkam, Kwasizur, J. H., Lacey, R., Lan, S., Landgraf, J. M., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Leung, Y. H., Li, C., Li, W., Li, X., Li, Y., Liang, Y., Licenik, R., Lin, T., Lin, Y., Lisa, M. A., Liu, F., Liu, H., Liu, P., Liu, T., Liu, X., Liu, Y., Liu, Z., Ljubicic, T., Llope, W. J., Longacre, R. S., Lukow, N. S., Luo, S., Luo, X., Ma, G. L., Ma, L., Ma, R., Ma, Y. G., Magdy, N., Majka, R., Mallick, D., Margetis, S., Markert, C., Matis, H. S., Mazer, J. A., Minaev, N. G., Mioduszewski, S., Mohanty, B., Mondal, M. M., Mooney, I., Moravcova, Z., Morozov, D. A., Nagy, M., Nam, J. D., Nasim, Md., Nayak, K., Neff, D., Nelson, J. M., Nemes, D. B., Nie, M., Nigmatkulov, G., Niida, T., Nogach, L. V., Nonaka, T., Nunes, A. S., Odyniec, G., Ogawa, A., Oh, S., Okorokov, V. A., Page, B. S., Pak, R., Pandav, A., Panebratsev, Y., Pawlik, B., Pawlowska, D., Pei, H., Perkins, C., Pinsky, L., Pintér, R. L., Pluta, J., Porter, J., Posik, M., Pruthi, N. K., Przybycien, M., Putschke, J., Qiu, H., Quintero, A., Radhakrishnan, S. K., Ramachandran, S., Ray, R. L., Reed, R., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ruan, L., Rusnak, J., Sahoo, N. R., Sako, H., Salur, S., Sandweiss, J., Sato, S., Schmidke, W. B., Schmitz, N., Schweid, B. R., Seck, F., Seger, J., Sergeeva, M., Seto, R., Seyboth, P., Shah, N., Shahaliev, E., Shanmuganathan, P. V., Shao, M., Shen, F., Shen, W. Q., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Sikora, R., Simko, M., Singh, J., Singha, S., Smirnov, N., Solyst, W., Sorensen, P., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Stefaniak, M., Stewart, D. J., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Sumbera, M., Summa, B., Sun, X. M., Sun, X., Sun, Y., Surrow, B., Svirida, D. N., Szymanski, P., Tang, A. H., Tang, Z., Taranenko, A., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Tlusty, D., Tokarev, M., Tomkiel, C. A., Trentalange, S., Tribble, R. E., Tribedy, P., Tripathy, S. K., Tsai, O. D., Tu, Z., Ullrich, T., Underwood, D. G., Upsal, I., Van Buren, G., Vanek, J., Vasiliev, A. N., Vassiliev, I., Videbæk, F., Vokal, S., Voloshin, S. A., Wang, F., Wang, G., Wang, J. S., Wang, P., Wang, Y., Wang, Z., Webb, J. C., Weidenkaff, P. C., Wen, L., Westfall, G. D., Wieman, H., Wissink, S. W., Witt, R., Wu, Y., Xiao, Z. G., Xie, G., Xie, W., Xu, H., Xu, N., Xu, Q. H., Xu, Y. F., Xu, Y., Xu, Z., Yang, C., Yang, Q., Yang, S., Yang, Y., Yang, Z., Ye, Z., Yi, L., Yip, K., Zbroszczyk, H., Zha, W., Zhang, C., Zhang, D., Zhang, S., Zhang, X. P., Zhang, Y., Zhang, Z. J., Zhang, Z., Zhao, J., Zhong, C., Zhou, C., Zhu, X., Zhu, Z., Zurek, M., and Zyzak, M.

Subjects
High Energy Physics - Experiment, Nuclear Experiment
Abstract

We report on new measurements of inclusive J/$\psi$ polarization at mid-rapidity in p+p collisions at $\sqrt{s}$ = 200 GeV by the STAR experiment at RHIC. The polarization parameters, $\lambda_\theta$, $\lambda_\phi$, and $\lambda_{\theta\phi}$, are measured as a function of transverse momentum ($p_T$) in both the Helicity and Collins-Soper (CS) reference frames within $p_T< 10$ GeV/$C$. Except for $\lambda_\theta$ in the CS frame at the highest measured $p_T$, all three polarization parameters are consistent with 0 in both reference frames without any strong $p_T$ dependence. Several model calculations are compared with data, and the one using the Color Glass Condensate effective field theory coupled with non-relativistic QCD gives the best overall description of the experimental results, even though other models cannot be ruled out due to experimental uncertainties., Comment: 14 pages, 11 figures

Published
2020
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12. Investigation of the linear and mode-coupled flow harmonics in Au+Au collisions at $\sqrt{\textit{s}_{NN}}$ = 200 GeV

Author

STAR Collaboration, Adam, J., Adamczyk, L., Adams, J. R., Adkins, J. K., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alekseev, I., Anderson, D. M., Aparin, A., Aschenauer, E. C., Ashraf, M. U., Atetalla, F. G., Attri, A., Averichev, G. S., Bairathi, V., Barish, K., Behera, A., Bellwied, R., Bhasin, A., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Brandenburg, J. D., Brandin, A. V., Butterworth, J., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Chakaberia, I., Chaloupka, P., Chan, B. K., Chang, F-H., Chang, Z., Chankova-Bunzarova, N., Chatterjee, A., Chen, D., Chen, J. H., Chen, X., Chen, Z., Cheng, J., Cherney, M., Chevalier, M., Choudhury, S., Christie, W., Chu, X., Crawford, H. J., Csanád, M., Daugherity, M., Dedovich, T. G., Deppner, I. M., Derevschikov, A. A., Didenko, L., Dong, X., Drachenberg, J. L., Dunlop, J. C., Edmonds, T., Elsey, N., Engelage, J., Eppley, G., Esha, R., Esumi, S., Evdokimov, O., Ewigleben, A., Eyser, O., Fatemi, R., Fazio, S., Federic, P., Fedorisin, J., Feng, C. J., Feng, Y., Filip, P., Finch, E., Fisyak, Y., Francisco, A., Fulek, L., Gagliardi, C. A., Galatyuk, T., Geurts, F., Gibson, A., Gopal, K., Grosnick, D., Guryn, W., Hamad, A. I., Hamed, A., Harabasz, S., Harris, J. W., He, S., He, W., He, X. H., Heppelmann, S., Herrmann, N., Hoffman, E., Holub, L., Hong, Y., Horvat, S., Hu, Y., Huang, H. Z., Huang, S. L., Huang, T., Huang, X., Humanic, T. J., Huo, P., Igo, G., Isenhower, D., Jacobs, W. W., Jena, C., Jentsch, A., JI, Y., Jia, J., Jiang, K., Jowzaee, S., Ju, X., Judd, E. G., Kabana, S., Kabir, M. L., Kagamaster, S., Kalinkin, D., Kang, K., Kapukchyan, D., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kelsey, M., Khyzhniak, Y. V., Kikoła, D. P., Kim, C., Kimelman, B., Kincses, D., Kinghorn, T. A., Kisel, I., Kiselev, A., Kocan, M., Kochenda, L., Kosarzewski, L. K., Kramarik, L., Kravtsov, P., Krueger, K., Mudiyanselage, N. Kulathunga, Kumar, L., Elayavalli, R. Kunnawalkam, Kwasizur, J. H., Lacey, R., Lan, S., Landgraf, J. M., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Leung, Y. H., Li, C., Li, W., Li, X., Li, Y., Liang, Y., Licenik, R., Lin, T., Lin, Y., Lisa, M. A., Liu, F., Liu, H., Liu, P., Liu, T., Liu, X., Liu, Y., Liu, Z., Ljubicic, T., Llope, W. J., Longacre, R. S., Lukow, N. S., Luo, S., Luo, X., Ma, G. L., Ma, L., Ma, R., Ma, Y. G., Magdy, N., Majka, R., Mallick, D., Margetis, S., Markert, C., Matis, H. S., Mazer, J. A., Minaev, N. G., Mioduszewski, S., Mohanty, B., Mondal, M. M., Mooney, I., Moravcova, Z., Morozov, D. A., Nagy, M., Nam, J. D., Nasim, Md., Nayak, K., Neff, D., Nelson, J. M., Nemes, D. B., Nie, M., Nigmatkulov, G., Niida, T., Nogach, L. V., Nonaka, T., Nunes, A. S., Odyniec, G., Ogawa, A., Oh, S., Okorokov, V. A., Page, B. S., Pak, R., Pandav, A., Panebratsev, Y., Pawlik, B., Pawlowska, D., Pei, H., Perkins, C., Pinsky, L., Pintér, R. L., Pluta, J., Porter, J., Posik, M., Pruthi, N. K., Przybycien, M., Putschke, J., Qiu, H., Quintero, A., Radhakrishnan, S. K., Ramachandran, S., Ray, R. L., Reed, R., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ruan, L., Rusnak, J., Sahoo, N. R., Sako, H., Salur, S., Sandweiss, J., Sato, S., Schmidke, W. B., Schmitz, N., Schweid, B. R., Seck, F., Seger, J., Sergeeva, M., Seto, R., Seyboth, P., Shah, N., Shahaliev, E., Shanmuganathan, P. V., Shao, M., Shen, F., Shen, W. Q., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Sikora, R., Simko, M., Singh, J., Singha, S., Smirnov, N., Solyst, W., Sorensen, P., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Stefaniak, M., Stewart, D. J., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Sumbera, M., Summa, B., Sun, X. M., Sun, X., Sun, Y., Surrow, B., Svirida, D. N., Szymanski, P., Tang, A. H., Tang, Z., Taranenko, A., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Tlusty, D., Tokarev, M., Tomkiel, C. A., Trentalange, S., Tribble, R. E., Tribedy, P., Tripathy, S. K., Tsai, O. D., Tu, Z., Ullrich, T., Underwood, D. G., Upsal, I., Van Buren, G., Vanek, J., Vasiliev, A. N., Vassiliev, I., Videbæk, F., Vokal, S., Voloshin, S. A., Wang, F., Wang, G., Wang, J. S., Wang, P., Wang, Y., Wang, Z., Webb, J. C., Weidenkaff, P. C., Wen, L., Westfall, G. D., Wieman, H., Wissink, S. W., Witt, R., Wu, Y., Xiao, Z. G., Xie, G., Xie, W., Xu, H., Xu, N., Xu, Q. H., Xu, Y. F., Xu, Y., Xu, Z., Yang, C., Yang, Q., Yang, S., Yang, Y., Yang, Z., Ye, Z., Yi, L., Yip, K., Zbroszczyk, H., Zha, W., Zhang, C., Zhang, D., Zhang, S., Zhang, X. P., Zhang, Y., Zhang, Z. J., Zhang, Z., Zhao, J., Zhong, C., Zhou, C., Zhu, X., Zhu, Z., Zurek, M., and Zyzak, M.

Subjects
Nuclear Experiment
Abstract

Flow harmonics ($\textit{v}_{n}$) of the Fourier expansion for the azimuthal distributions of hadrons are commonly employed to quantify the azimuthal anisotropy of particle production relative to the collision symmetry planes. While lower order Fourier coefficients ($\textit{v}_{2}$ and $\textit{v}_{3}$) are more directly related to the corresponding eccentricities of the initial state, the higher-order flow harmonics ($\textit{v}_{n>3}$) can be induced by a mode-coupled response to the lower-order anisotropies, in addition to a linear response to the same-order anisotropies. These higher-order flow harmonics and their linear and mode-coupled contributions can be used to more precisely constrain the initial conditions and the transport properties of the medium in theoretical models. The multiparticle azimuthal cumulant method is used to measure the linear and mode-coupled contributions in the higher-order anisotropic flow, the mode-coupled response coefficients, and the correlations of the event plane angles for charged particles as functions of centrality and transverse momentum in Au+Au collisions at nucleon-nucleon center-of-mass energy $\sqrt{\textit{s}_{NN}}$ = 200 GeV. The results are compared to similar LHC measurements as well as to several viscous hydrodynamic calculations with varying initial conditions., Comment: 15 pages, 4 figures, submitted for publication

Published
2020
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13. Pair invariant mass to isolate background in the search for the chiral magnetic effect in Au+Au collisions at $\sqrt{s_{_{\rm NN}}}$= 200 GeV

Author

STAR Collaboration, Adam, J., Adamczyk, L., Adams, J. R., Adkins, J. K., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alekseev, I., Anderson, D. M., Aparin, A., Aschenauer, E. C., Ashraf, M. U., Atetalla, F. G., Attri, A., Averichev, G. S., Bairathi, V., Barish, K., Behera, A., Bellwied, R., Bhasin, A., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Brandenburg, J. D., Brandin, A. V., Butterworth, J., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Chakaberia, I., Chaloupka, P., Chan, B. K., Chang, F-H., Chang, Z., Chankova-Bunzarova, N., Chatterjee, A., Chen, D., Chen, J. H., Chen, X., Chen, Z., Cheng, J., Cherney, M., Chevalier, M., Choudhury, S., Christie, W., Chu, X., Crawford, H. J., Csanád, M., Daugherity, M., Dedovich, T. G., Deppner, I. M., Derevschikov, A. A., Didenko, L., Dong, X., Drachenberg, J. L., Dunlop, J. C., Edmonds, T., Elsey, N., Engelage, J., Eppley, G., Esha, R., Esumi, S., Evdokimov, O., Ewigleben, A., Eyser, O., Fatemi, R., Fazio, S., Federic, P., Fedorisin, J., Feng, C. J., Feng, Y., Filip, P., Finch, E., Fisyak, Y., Francisco, A., Fulek, L., Gagliardi, C. A., Galatyuk, T., Geurts, F., Gibson, A., Gopal, K., Grosnick, D., Guryn, W., Hamad, A. I., Hamed, A., Harabasz, S., Harris, J. W., He, S., He, W., He, X. H., Heppelmann, S., Herrmann, N., Hoffman, E., Holub, L., Hong, Y., Horvat, S., Hu, Y., Huang, H. Z., Huang, S. L., Huang, T., Huang, X., Humanic, T. J., Huo, P., Igo, G., Isenhower, D., Jacobs, W. W., Jena, C., Jentsch, A., JI, Y., Jia, J., Jiang, K., Jowzaee, S., Ju, X., Judd, E. G., Kabana, S., Kabir, M. L., Kagamaster, S., Kalinkin, D., Kang, K., Kapukchyan, D., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kelsey, M., Khyzhniak, Y. V., Kikoła, D. P., Kim, C., Kimelman, B., Kincses, D., Kinghorn, T. A., Kisel, I., Kiselev, A., Kisiel, A., Kocan, M., Kochenda, L., Kosarzewski, L. K., Kramarik, L., Kravtsov, P., Krueger, K., Mudiyanselage, N. Kulathunga, Kumar, L., Elayavalli, R. Kunnawalkam, Kwasizur, J. H., Lacey, R., Lan, S., Landgraf, J. M., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Leung, Y. H., Li, C., Li, W., Li, X., Li, Y., Liang, Y., Licenik, R., Lin, T., Lin, Y., Lisa, M. A., Liu, F., Liu, H., Liu, P., Liu, T., Liu, X., Liu, Y., Liu, Z., Ljubicic, T., Llope, W. J., Longacre, R. S., Lukow, N. S., Luo, S., Luo, X., Ma, G. L., Ma, L., Ma, R., Ma, Y. G., Magdy, N., Majka, R., Mallick, D., Margetis, S., Markert, C., Matis, H. S., Mazer, J. A., Minaev, N. G., Mioduszewski, S., Mohanty, B., Mondal, M. M., Mooney, I., Moravcova, Z., Morozov, D. A., Nagy, M., Nam, J. D., Nasim, Md., Nayak, K., Neff, D., Nelson, J. M., Nemes, D. B., Nie, M., Nigmatkulov, G., Niida, T., Nogach, L. V., Nonaka, T., Nunes, A. S., Odyniec, G., Ogawa, A., Oh, S., Okorokov, V. A., Page, B. S., Pak, R., Pandav, A., Panebratsev, Y., Pawlik, B., Pawlowska, D., Pei, H., Perkins, C., Pinsky, L., Pintér, R. L., Pluta, J., Porter, J., Posik, M., Pruthi, N. K., Przybycien, M., Putschke, J., Qiu, H., Quintero, A., Radhakrishnan, S. K., Ramachandran, S., Ray, R. L., Reed, R., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ruan, L., Rusnak, J., Sahoo, N. R., Sako, H., Salur, S., Sandweiss, J., Sato, S., Schmidke, W. B., Schmitz, N., Schweid, B. R., Seck, F., Seger, J., Sergeeva, M., Seto, R., Seyboth, P., Shah, N., Shahaliev, E., Shanmuganathan, P. V., Shao, M., Shen, F., Shen, W. Q., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Sikora, R., Simko, M., Singh, J., Singha, S., Smirnov, N., Solyst, W., Sorensen, P., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Stefaniak, M., Stewart, D. J., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Sumbera, M., Summa, B., Sun, X. M., Sun, X., Sun, Y., Surrow, B., Svirida, D. N., Szymanski, P., Tang, A. H., Tang, Z., Taranenko, A., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Tlusty, D., Tokarev, M., Tomkiel, C. A., Trentalange, S., Tribble, R. E., Tribedy, P., Tripathy, S. K., Tsai, O. D., Tu, Z., Ullrich, T., Underwood, D. G., Upsal, I., Van Buren, G., Vanek, J., Vasiliev, A. N., Vassiliev, I., Videbæk, F., Vokal, S., Voloshin, S. A., Wang, F., Wang, G., Wang, J. S., Wang, P., Wang, Y., Wang, Z., Webb, J. C., Weidenkaff, P. C., Wen, L., Westfall, G. D., Wieman, H., Wissink, S. W., Witt, R., Wu, Y., Xiao, Z. G., Xie, G., Xie, W., Xu, H., Xu, N., Xu, Q. H., Xu, Y. F., Xu, Y., Xu, Z., Yang, C., Yang, Q., Yang, S., Yang, Y., Yang, Z., Ye, Z., Yi, L., Yip, K., Zbroszczyk, H., Zha, W., Zhang, D., Zhang, S., Zhang, X. P., Zhang, Y., Zhang, Z. J., Zhang, Z., Zhao, J., Zhong, C., Zhou, C., Zhu, X., Zhu, Z., Zurek, M., and Zyzak, M.

Subjects
Nuclear Experiment, High Energy Physics - Experiment, Nuclear Theory
Abstract

Quark interactions with topological gluon configurations can induce local chirality imbalance and parity violation in quantum chromodynamics, which can lead to the chiral magnetic effect (CME) -- an electric charge separation along the strong magnetic field in relativistic heavy-ion collisions. The CME-sensitive azimuthal correlator observable ($\Delta\gamma$) is contaminated by background arising, in part, from resonance decays coupled with elliptic anisotropy ($v_{2}$). We report here differential measurements of the correlator as a function of the pair invariant mass ($m_{\rm inv}$) in 20-50\% centrality Au+Au collisions at $\sqrt{s_{_{\rm NN}}}$= 200 GeV by the STAR experiment at RHIC. Strong resonance background contributions to $\Delta\gamma$ are observed. At large $m_{\rm inv}$ where this background is significantly reduced, the $\Delta\gamma$ value is found to be significantly smaller. An event-shape-engineering technique is deployed to determine the $v_{2}$ background shape as a function of $m_{\rm inv}$. We extract a $v_2$-independent and $m_{\rm inv}$-averaged signal $\Delta\gamma_{\rm sig}$ = (0.03 $\pm$ 0.06 $\pm$ 0.08) $\times10^{-4}$, or $(2\pm4\pm5)\%$ of the inclusive $\Delta\gamma(m_{\rm inv}>0.4$ GeV/$c^2$)$ =(1.58 \pm 0.02 \pm 0.02) \times10^{-4}$, within pion $p_{T}$ = 0.2 - 0.8~\gevc and averaged over pseudorapidity ranges of $-1 < \eta < -0.05$ and $0.05 < \eta < 1$. This represents an upper limit of $0.23\times10^{-4}$, or $15\%$ of the inclusive result, at $95\%$ confidence level for the $m_{\rm inv}$-integrated CME contribution., Comment: PRC published version

Published
2020
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14. Measurement of inclusive charged-particle jet production in Au+Au collisions at $\sqrt{s_{NN}}$=200 GeV

Author

STAR Collaboration, Adam, J., Adamczyk, L., Adams, J. R., Adkins, J. K., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alekseev, I., Anderson, D. M., Aparin, A., Aschenauer, E. C., Ashraf, M. U., Atetalla, F. G., Attri, A., Averichev, G. S., Bairathi, V., Barish, K., Behera, A., Bellwied, R., Bhasin, A., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Brandenburg, J. D., Brandin, A. V., Butterworth, J., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Chakaberia, I., Chaloupka, P., Chan, B. K., Chang, F-H., Chang, Z., Chankova-Bunzarova, N., Chatterjee, A., Chen, D., Chen, J. H., Chen, X., Chen, Z., Cheng, J., Cherney, M., Chevalier, M., Choudhury, S., Christie, W., Chu, X., Crawford, H. J., Csanád, M., Daugherity, M., Dedovich, T. G., Deppner, I. M., Derevschikov, A. A., Didenko, L., Dong, X., Drachenberg, J. L., Dunlop, J. C., Edmonds, T., Elsey, N., Engelage, J., Eppley, G., Esha, R., Esumi, S., Evdokimov, O., Ewigleben, A., Eyser, O., Fatemi, R., Fazio, S., Federic, P., Fedorisin, J., Feng, C. J., Feng, Y., Filip, P., Finch, E., Fisyak, Y., Francisco, A., Fulek, L., Gagliardi, C. A., Galatyuk, T., Geurts, F., Gibson, A., Gopal, K., Grosnick, D., Guryn, W., Hamad, A. I., Hamed, A., Harabasz, S., Harris, J. W., He, S., He, W., He, X., Heppelmann, S., Herrmann, N., Hoffman, E., Holub, L., Hong, Y., Horvat, S., Hu, Y., Huang, H. Z., Huang, S. L., Huang, T., Huang, X., Humanic, T. J., Huo, P., Igo, G., Isenhower, D., Jacobs, P. M., Jacobs, W. W., Jena, C., Jentsch, A., JI, Y., Jia, J., Jiang, K., Jowzaee, S., Ju, X., Judd, E. G., Kabana, S., Kabir, M. L., Kagamaster, S., Kalinkin, D., Kang, K., Kapukchyan, D., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kelsey, M., Khyzhniak, Y. V., Kikoła, D. P., Kim, C., Kimelman, B., Kincses, D., Kinghorn, T. A., Kisel, I., Kiselev, A., Kisiel, A., Kocan, M., Kochenda, L., Kosarzewski, L. K., Kramarik, L., Kravtsov, P., Krueger, K., Mudiyanselage, N. Kulathunga, Kumar, L., Elayavalli, R. Kunnawalkam, Kwasizur, J. H., Lacey, R., Lan, S., Landgraf, J. M., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Leung, Y. H., Li, C., Li, W., Li, X., Li, Y., Liang, Y., Licenik, R., Lin, T., Lin, Y., Lisa, M. A., Liu, F., Liu, H., Liu, P., Liu, T., Liu, X., Liu, Y., Liu, Z., Ljubicic, T., Llope, W. J., Longacre, R. S., Lukow, N. S., Luo, S., Luo, X., Ma, G. L., Ma, L., Ma, R., Ma, Y. G., Magdy, N., Majka, R., Mallick, D., Margetis, S., Markert, C., Matis, H. S., Mazer, J. A., Minaev, N. G., Mioduszewski, S., Mohanty, B., Mondal, M. M., Mooney, I., Moravcova, Z., Morozov, D. A., Nagy, M., Nam, J. D., Nasim, Md., Nayak, K., Neff, D., Nelson, J. M., Nemes, D. B., Nie, M., Nigmatkulov, G., Niida, T., Nogach, L. V., Nonaka, T., Odyniec, G., Ogawa, A., Oh, S., Okorokov, V. A., Page, B. S., Pak, R., Pandav, A., Panebratsev, Y., Pawlik, B., Pawlowska, D., Pei, H., Perkins, C., Pinsky, L., Pintér, R. L., Pluta, J., Porter, J., Posik, M., Pruthi, N. K., Przybycien, M., Putschke, J., Qiu, H., Quintero, A., Radhakrishnan, S. K., Ramachandran, S., Ray, R. L., Reed, R., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ruan, L., Rusnak, J., Sahoo, N. R., Sako, H., Salur, S., Sandweiss, J., Sato, S., Schmidke, W. B., Schmitz, N., Schweid, B. R., Seck, F., Seger, J., Sergeeva, M., Seto, R., Seyboth, P., Shah, N., Shahaliev, E., Shanmuganathan, P. V., Shao, M., Shen, F., Shen, W. Q., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Sikora, R., Simko, M., Singh, J., Singha, S., Smirnov, N., Solyst, W., Sorensen, P., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Stefaniak, M., Stewart, D. J., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Sumbera, M., Summa, B., Sun, X. M., Sun, X., Sun, Y., Surrow, B., Svirida, D. N., Szymanski, P., Tang, A. H., Tang, Z., Taranenko, A., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Tlusty, D., Tokarev, M., Tomkiel, C. A., Trentalange, S., Tribble, R. E., Tribedy, P., Tripathy, S. K., Tsai, O. D., Tu, Z., Ullrich, T., Underwood, D. G., Upsal, I., Van Buren, G., Vanek, J., Vasiliev, A. N., Vassiliev, I., Videbæk, F., Vokal, S., Voloshin, S. A., Wang, F., Wang, G., Wang, J. S., Wang, P., Wang, Y., Wang, Z., Webb, J. C., Weidenkaff, P. C., Wen, L., Westfall, G. D., Wieman, H., Wissink, S. W., Witt, R., Wu, Y., Xiao, Z. G., Xie, G., Xie, W., Xu, H., Xu, N., Xu, Q. H., Xu, Y. F., Xu, Y., Xu, Z., Yang, C., Yang, Q., Yang, S., Yang, Y., Yang, Z., Ye, Z., Yi, L., Yip, K., Zbroszczyk, H., Zha, W., Zhang, D., Zhang, S., Zhang, X. P., Zhang, Y., Zhang, Z. J., Zhang, Z., Zhao, J., Zhong, C., Zhou, C., Zhu, X., Zhu, Z., Zurek, M., and Zyzak, M.

Subjects
Nuclear Experiment, High Energy Physics - Experiment
Abstract

The STAR Collaboration at the Relativistic Heavy Ion Collider reports the first measurement of inclusive jet production in peripheral and central Au+Au collisions at $\sqrt{s_{NN}}$=200 GeV. Jets are reconstructed with the anti-k$_{T}$ algorithm using charged tracks with pseudorapidity $|\eta|<1.0$ and transverse momentum $0.2

Published
2020
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15. Measurement of the central exclusive production of charged particle pairs in proton-proton collisions at $\sqrt{s} = 200$ GeV with the STAR detector at RHIC

Author

STAR Collaboration, Adam, J., Adamczyk, L., Adams, J. R., Adkins, J. K., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alekseev, I., Anderson, D. M., Aparin, A., Aschenauer, E. C., Ashraf, M. U., Atetalla, F. G., Attri, A., Averichev, G. S., Bairathi, V., Barish, K., Behera, A., Bellwied, R., Bhasin, A., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Brandenburg, J. D., Brandin, A. V., Butterworth, J., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Chakaberia, I., Chaloupka, P., Chan, B. K., Chang, F-H., Chang, Z., Chankova-Bunzarova, N., Chatterjee, A., Chen, D., Chen, J. H., Chen, X., Chen, Z., Cheng, J., Cherney, M., Chevalier, M., Choudhury, S., Christie, W., Chu, X., Crawford, H. J., Csanád, M., Daugherity, M., Dedovich, T. G., Deppner, I. M., Derevschikov, A. A., Didenko, L., Dong, X., Drachenberg, J. L., Dunlop, J. C., Edmonds, T., Elsey, N., Engelage, J., Eppley, G., Esha, R., Esumi, S., Evdokimov, O., Ewigleben, A., Eyser, O., Fatemi, R., Fazio, S., Federic, P., Fedorisin, J., Feng, C. J., Feng, Y., Filip, P., Finch, E., Fisyak, Y., Francisco, A., Fulek, L., Gagliardi, C. A., Galatyuk, T., Geurts, F., Gibson, A., Gopal, K., Grosnick, D., Guryn, W., Hamad, A. I., Hamed, A., Harabasz, S., Harris, J. W., He, S., He, W., He, X. H., Heppelmann, S., Herrmann, N., Hoffman, E., Holub, L., Hong, Y., Horvat, S., Hu, Y., Huang, H. Z., Huang, S. L., Huang, T., Huang, X., Humanic, T. J., Huo, P., Igo, G., Isenhower, D., Jacobs, W. W., Jena, C., Jentsch, A., JI, Y., Jia, J., Jiang, K., Jowzaee, S., Ju, X., Judd, E. G., Kabana, S., Kabir, M. L., Kagamaster, S., Kalinkin, D., Kang, K., Kapukchyan, D., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kelsey, M., Khyzhniak, Y. V., Kikoła, D. P., Kim, C., Kimelman, B., Kincses, D., Kinghorn, T. A., Kisel, I., Kiselev, A., Kisiel, A., Kocan, M., Kochenda, L., Kosarzewski, L. K., Kramarik, L., Kravtsov, P., Krueger, K., Mudiyanselage, N. Kulathunga, Kumar, L., Elayavalli, R. Kunnawalkam, Kwasizur, J. H., Lacey, R., Lan, S., Landgraf, J. M., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Leung, Y. H., Li, C., Li, W., Li, X., Li, Y., Liang, Y., Licenik, R., Lin, T., Lin, Y., Lisa, M. A., Liu, F., Liu, H., Liu, P., Liu, T., Liu, X., Liu, Y., Liu, Z., Ljubicic, T., Llope, W. J., Longacre, R. S., Lukow, N. S., Luo, S., Luo, X., Ma, G. L., Ma, L., Ma, R., Ma, Y. G., Magdy, N., Majka, R., Mallick, D., Margetis, S., Markert, C., Matis, H. S., Mazer, J. A., Minaev, N. G., Mioduszewski, S., Mohanty, B., Mondal, M. M., Mooney, I., Moravcova, Z., Morozov, D. A., Nagy, M., Nam, J. D., Nasim, Md., Nayak, K., Neff, D., Nelson, J. M., Nemes, D. B., Nie, M., Nigmatkulov, G., Niida, T., Nogach, L. V., Nonaka, T., Nunes, A. S., Odyniec, G., Ogawa, A., Oh, S., Okorokov, V. A., Page, B. S., Pak, R., Pandav, A., Panebratsev, Y., Pawlik, B., Pawlowska, D., Pei, H., Perkins, C., Pinsky, L., Pintér, R. L., Pluta, J., Porter, J., Posik, M., Pruthi, N. K., Przybycien, M., Putschke, J., Qiu, H., Quintero, A., Radhakrishnan, S. K., Ramachandran, S., Ray, R. L., Reed, R., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ruan, L., Rusnak, J., Sahoo, N. R., Sako, H., Salur, S., Sandweiss, J., Sato, S., Schmidke, W. B., Schmitz, N., Schweid, B. R., Seck, F., Seger, J., Sergeeva, M., Seto, R., Seyboth, P., Shah, N., Shahaliev, E., Shanmuganathan, P. V., Shao, M., Shen, F., Shen, W. Q., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Sikora, R., Simko, M., Singh, J., Singha, S., Smirnov, N., Solyst, W., Sorensen, P., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Stefaniak, M., Stewart, D. J., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Sumbera, M., Summa, B., Sun, X. M., Sun, X., Sun, Y., Surrow, B., Svirida, D. N., Szymanski, P., Tang, A. H., Tang, Z., Taranenko, A., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Tlusty, D., Tokarev, M., Tomkiel, C. A., Trentalange, S., Tribble, R. E., Tribedy, P., Tripathy, S. K., Tsai, O. D., Tu, Z., Ullrich, T., Underwood, D. G., Upsal, I., Van Buren, G., Vanek, J., Vasiliev, A. N., Vassiliev, I., Videbæk, F., Vokal, S., Voloshin, S. A., Wang, F., Wang, G., Wang, J. S., Wang, P., Wang, Y., Wang, Z., Webb, J. C., Weidenkaff, P. C., Wen, L., Westfall, G. D., Wieman, H., Wissink, S. W., Witt, R., Wu, Y., Xiao, Z. G., Xie, G., Xie, W., Xu, H., Xu, N., Xu, Q. H., Xu, Y. F., Xu, Y., Xu, Z., Yang, C., Yang, Q., Yang, S., Yang, Y., Yang, Z., Ye, Z., Yi, L., Yip, K., Zbroszczyk, H., Zha, W., Zhang, D., Zhang, S., Zhang, X. P., Zhang, Y., Zhang, Z. J., Zhang, Z., Zhao, J., Zhong, C., Zhou, C., Zhu, X., Zhu, Z., Zurek, M., and Zyzak, M.

Subjects
High Energy Physics - Experiment, Nuclear Experiment
Abstract

We report on the measurement of the Central Exclusive Production of charged particle pairs $h^{+}h^{-}$ ($h = \pi, K, p$) with the STAR detector at RHIC in proton-proton collisions at $\sqrt{s} = 200$ GeV. The charged particle pairs produced in the reaction $pp\to p^\prime+h^{+}h^{-}+p^\prime$ are reconstructed from the tracks in the central detector, while the forward-scattered protons are measured in the Roman Pot system. Differential cross sections are measured in the fiducial region, which roughly corresponds to the square of the four-momentum transfers at the proton vertices in the range $0.04~\mbox{GeV}^2 < -t_1 , -t_2 < 0.2~\mbox{GeV}^2$, invariant masses of the charged particle pairs up to a few GeV and pseudorapidities of the centrally-produced hadrons in the range $|\eta|<0.7$. The measured cross sections are compared to phenomenological predictions based on the Double Pomeron Exchange (DPE) model. Structures observed in the mass spectra of $\pi^{+}\pi^{-}$ and $K^{+}K^{-}$ pairs are consistent with the DPE model, while angular distributions of pions suggest a dominant spin-0 contribution to $\pi^{+}\pi^{-}$ production. The fiducial $\pi^+\pi^-$ cross section is extrapolated to the Lorentz-invariant region, which allows decomposition of the invariant mass spectrum into continuum and resonant contributions. The extrapolated cross section is well described by the continuum production and at least three resonances, the $f_0(980)$, $f_2(1270)$ and $f_0(1500)$, with a possible small contribution from the $f_0(1370)$. Fits to the extrapolated differential cross section as a function of $t_1$ and $t_2$ enable extraction of the exponential slope parameters in several bins of the invariant mass of $\pi^+\pi^-$ pairs. These parameters are sensitive to the size of the interaction region., Comment: Published in Journal of High Energy Physics

Published
2020
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16. Results on Total and Elastic Cross Sections in Proton-Proton Collisions at $\sqrt{s} = 200$ GeV

Author

STAR Collaboration, Adam, J., Adamczyk, L., Adams, J. R., Adkins, J. K., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alekseev, I., Anderson, D. M., Aparin, A., Aschenauer, E. C., Ashraf, M. U., Atetalla, F. G., Attri, A., Averichev, G. S., Bairathi, V., Barish, K., Behera, A., Bellwied, R., Bhasin, A., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Brandenburg, J. D., Brandin, A. V., Bueltmann, S., Butterworth, J., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Chakaberia, I., Chaloupka, P., Chan, B. K., Chang, F-H., Chang, Z., Chankova-Bunzarova, N., Chatterjee, A., Chen, D., Chen, J. H., Chen, X., Chen, Z., Cheng, J., Cherney, M., Chevalier, M., Choudhury, S., Christie, W., Chu, X., Crawford, H. J., Csanád, M., Daugherity, M., Dedovich, T. G., Deppner, I. M., Derevschikov, A. A., Didenko, L., Dong, X., Drachenberg, J. L., Dunlop, J. C., Edmonds, T., Elsey, N., Engelage, J., Eppley, G., Esumi, S., Evdokimov, O., Ewigleben, A., Eyser, O., Fatemi, R., Fazio, S., Federic, P., Fedorisin, J., Feng, C. J., Feng, Y., Filip, P., Finch, E., Fisyak, Y., Francisco, A., Fulek, L., Gagliardi, C. A., Galatyuk, T., Geurts, F., Gibson, A., Gopal, K., Grosnick, D., Guryn, W., Hamad, A. I., Hamed, A., Harabasz, S., Harris, J. W., He, S., He, W., He, X. H., Heppelmann, S., Herrmann, N., Hoffman, E., Holub, L., Hong, Y., Horvat, S., Hu, Y., Huang, H. Z., Huang, S. L., Huang, T., Huang, X., Humanic, T. J., Huo, P., Igo, G., Isenhower, D., Jacobs, W. W., Jena, C., Jentsch, A., JI, Y., Jia, J., Jiang, K., Jowzaee, S., Ju, X., Judd, E. G., Kabana, S., Kabir, M. L., Kagamaster, S., Kalinkin, D., Kang, K., Kapukchyan, D., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kelsey, M., Khyzhniak, Y. V., Kikoła, D. P., Kim, C., Kimelman, B., Kincses, D., Kinghorn, T. A., Kisel, I., Kiselev, A., Kocan, M., Kochenda, L., Kosarzewski, L. K., Kramarik, L., Kravtsov, P., Krueger, K., Mudiyanselage, N. Kulathunga, Kumar, L., Kumar, S., Elayavalli, R. Kunnawalkam, Kwasizur, J. H., Lacey, R., Lan, S., Landgraf, J. M., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Leung, Y. H., Li, C., Li, W., Li, X., Li, Y., Liang, Y., Licenik, R., Lin, T., Lin, Y., Lisa, M. A., Liu, F., Liu, H., Liu, P., Liu, T., Liu, X., Liu, Y., Liu, Z., Ljubicic, T., Llope, W. J., Longacre, R. S., Lukow, N. S., Luo, S., Luo, X., Ma, G. L., Ma, L., Ma, R., Ma, Y. G., Magdy, N., Majka, R., Mallick, D., Margetis, S., Markert, C., Matis, H. S., Mazer, J. A., Minaev, N. G., Mioduszewski, S., Mohanty, B., Mooney, I., Moravcova, Z., Morozov, D. A., Nagy, M., Nam, J. D., Nasim, Md., Nayak, K., Neff, D., Nelson, J. M., Nemes, D. B., Nie, M., Nigmatkulov, G., Niida, T., Nogach, L. V., Nonaka, T., Nunes, A. S., Odyniec, G., Ogawa, A., Oh, S., Okorokov, V. A., Page, B. S., Pak, R., Pandav, A., Panebratsev, Y., Pawlik, B., Pawlowska, D., Pei, H., Perkins, C., Pinsky, L., Pintér, R. L., Pluta, J., Porter, J., Posik, M., Pruthi, N. K., Przybycien, M., Putschke, J., Qiu, H., Quintero, A., Radhakrishnan, S. K., Ramachandran, S., Ray, R. L., Reed, R., Ritter, H. G., Rogachevskiy, O. V., Romero, J. L., Ruan, L., Rusnak, J., Sahoo, N. R., Sako, H., Salur, S., Sandweiss, J., Sato, S., Schmidke, W. B., Schmitz, N., Schweid, B. R., Seck, F., Seger, J., Sergeeva, M., Seto, R., Seyboth, P., Shah, N., Shahaliev, E., Shanmuganathan, P. V., Shao, M., Sheikh, A. I., Shen, F., Shen, W. Q., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Sikora, R., Simko, M., Singh, J., Singha, S., Smirnov, N., Solyst, W., Sorensen, P., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Stefaniak, M., Stewart, D. J., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Sumbera, M., Summa, B., Sun, X. M., Sun, X., Sun, Y., Surrow, B., Svirida, D. N., Szymanski, P., Tang, A. H., Tang, Z., Taranenko, A., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Tlusty, D., Tokarev, M., Tomkiel, C. A., Trentalange, S., Tribble, R. E., Tribedy, P., Tripathy, S. K., Tsai, O. D., Tu, Z., Ullrich, T., Underwood, D. G., Upsal, I., Van Buren, G., Vanek, J., Vasiliev, A. N., Vassiliev, I., Videbæk, F., Vokal, S., Voloshin, S. A., Wang, F., Wang, G., Wang, J. S., Wang, P., Wang, Y., Wang, Z., Webb, J. C., Weidenkaff, P. C., Wen, L., Westfall, G. D., Wieman, H., Wissink, S. W., Witt, R., Wu, Y., Xiao, Z. G., Xie, G., Xie, W., Xu, H., Xu, N., Xu, Q. H., Xu, Y. F., Xu, Y., Xu, Z., Yang, C., Yang, Q., Yang, S., Yang, Y., Yang, Z., Ye, Z., Yi, L., Yip, K., Zbroszczyk, H., Zha, W., Zhang, C., Zhang, D., Zhang, S., Zhang, X. P., Zhang, Y., Zhang, Z. J., Zhang, Z., Zhao, J., Zhong, C., Zhou, C., Zhu, X., Zhu, Z., Zurek, M., and Zyzak, M.

Subjects
High Energy Physics - Experiment, Nuclear Experiment
Abstract

We report results on the total and elastic cross sections in proton-proton collisions at $\sqrt{s}=200$ GeV obtained with the Roman Pot setup of the STAR experiment at the Relativistic Heavy Ion Collider (RHIC). The elastic differential cross section was measured in the squared four-momentum transfer range $0.045 \leq -t \leq 0.135$ GeV$^2$. The value of the exponential slope parameter $B$ of the elastic differential cross section $d\sigma/dt \sim e^{-Bt}$ in the measured $-t$ range was found to be $B = 14.32 \pm 0.09 (stat.)^{\scriptstyle +0.13}_{\scriptstyle -0.28} (syst.)$ GeV$^{-2}$. The total cross section $\sigma_{tot}$, obtained from extrapolation of the $d\sigma/dt$ to the optical point at $-t = 0$, is $\sigma_{tot} = 54.67 \pm 0.21 (stat.) ^{\scriptstyle +1.28}_{\scriptstyle -1.38} (syst.)$ mb. We also present the values of the elastic cross section $\sigma_{el} = 10.85 \pm 0.03 (stat.) ^{\scriptstyle +0.49}_{\scriptstyle -0.41}(syst.)$ mb, the elastic cross section integrated within the STAR $t$-range $\sigma^{det}_{el} = 4.05 \pm 0.01 (stat.) ^{\scriptstyle+0.18}_{\scriptstyle -0.17}(syst.)$ mb, and the inelastic cross section $\sigma_{inel} = 43.82 \pm 0.21 (stat.) ^{\scriptstyle +1.37}_{\scriptstyle -1.44} (syst.)$ mb. The results are compared with the world data., Comment: Updated version. New figure 4 and updated text. Accepted for publication in Phys. Lett. B

Published
2020
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17. Measurement of Groomed Jet Substructure Observables in \pp Collisions at $\sqrt{s} = 200$ GeV with STAR

Author

STAR Collaboration, Adam, J., Adamczyk, L., Adams, J. R., Adkins, J. K., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alekseev, I., Anderson, D. M., Aparin, A., Aschenauer, E. C., Ashraf, M. U., Atetalla, F. G., Attri, A., Averichev, G. S., Bairathi, V., Barish, K., Behera, A., Bellwied, R., Bhasin, A., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Brandenburg, J. D., Brandin, A. V., Butterworth, J., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Chakaberia, I., Chaloupka, P., Chan, B. K., Chang, F-H., Chang, Z., Chankova-Bunzarova, N., Chatterjee, A., Chen, D., Chen, J. H., Chen, X., Chen, Z., Cheng, J., Cherney, M., Chevalier, M., Choudhury, S., Christie, W., Crawford, H. J., Csanád, M., Daugherity, M., Dedovich, T. G., Deppner, I. M., Derevschikov, A. A., Didenko, L., Dong, X., Drachenberg, J. L., Dunlop, J. C., Edmonds, T., Elsey, N., Engelage, J., Eppley, G., Esha, R., Esumi, S., Evdokimov, O., Ewigleben, A., Eyser, O., Fatemi, R., Fazio, S., Federic, P., Fedorisin, J., Feng, C. J., Feng, Y., Filip, P., Finch, E., Fisyak, Y., Francisco, A., Fulek, L., Gagliardi, C. A., Galatyuk, T., Geurts, F., Gibson, A., Gopal, K., Grosnick, D., Guryn, W., Hamad, A. I., Hamed, A., Harris, J. W., He, S., He, W., He, X., Heppelmann, S., Herrmann, N., Hoffman, E., Holub, L., Hong, Y., Horvat, S., Hu, Y., Huang, H. Z., Huang, S. L., Huang, T., Huang, X., Humanic, T. J., Huo, P., Igo, G., Isenhower, D., Jacobs, W. W., Jena, C., Jentsch, A., JI, Y., Jia, J., Jiang, K., Jowzaee, S., Ju, X., Judd, E. G., Kabana, S., Kabir, M. L., Kagamaster, S., Kalinkin, D., Kang, K., Kapukchyan, D., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kelsey, M., Khyzhniak, Y. V., Kikoła, D. P., Kim, C., Kimelman, B., Kincses, D., Kinghorn, T. A., Kisel, I., Kiselev, A., Kisiel, A., Kocan, M., Kochenda, L., Kosarzewski, L. K., Kramarik, L., Kravtsov, P., Krueger, K., Mudiyanselage, N. Kulathunga, Kumar, L., Elayavalli, R. Kunnawalkam, Kwasizur, J. H., Lacey, R., Lan, S., Landgraf, J. M., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Leung, Y. H., Li, C., Li, W., Li, X., Li, Y., Liang, Y., Licenik, R., Lin, T., Lin, Y., Lisa, M. A., Liu, F., Liu, H., Liu, P., Liu, T., Liu, X., Liu, Y., Liu, Z., Ljubicic, T., Llope, W. J., Longacre, R. S., Lukow, N. S., Luo, S., Luo, X., Ma, G. L., Ma, L., Ma, R., Ma, Y. G., Magdy, N., Majka, R., Mallick, D., Margetis, S., Markert, C., Matis, H. S., Mazer, J. A., Minaev, N. G., Mioduszewski, S., Mohanty, B., Mondal, M. M., Mooney, I., Moravcova, Z., Morozov, D. A., Nagy, M., Nam, J. D., Nasim, Md., Nayak, K., Neff, D., Nelson, J. M., Nemes, D. B., Nie, M., Nigmatkulov, G., Niida, T., Nogach, L. V., Nonaka, T., Odyniec, G., Ogawa, A., Oh, S., Okorokov, V. A., Page, B. S., Pak, R., Pandav, A., Panebratsev, Y., Pawlik, B., Pawlowska, D., Pei, H., Perkins, C., Pinsky, L., Pintér, R. L., Pluta, J., Porter, J., Posik, M., Pruthi, N. K., Przybycien, M., Putschke, J., Qiu, H., Quintero, A., Radhakrishnan, S. K., Ramachandran, S., Ray, R. L., Reed, R., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ruan, L., Rusnak, J., Sahoo, N. R., Sako, H., Salur, S., Sandweiss, J., Sato, S., Schmidke, W. B., Schmitz, N., Schweid, B. R., Seck, F., Seger, J., Sergeeva, M., Seto, R., Seyboth, P., Shah, N., Shahaliev, E., Shanmuganathan, P. V., Shao, M., Shen, F., Shen, W. Q., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Sikora, R., Simko, M., Singh, J., Singha, S., Smirnov, N., Solyst, W., Sorensen, P., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Stefaniak, M., Stewart, D. J., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Sumbera, M., Summa, B., Sun, X. M., Sun, Y., Surrow, B., Svirida, D. N., Szymanski, P., Tang, A. H., Tang, Z., Taranenko, A., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Tlusty, D., Tokarev, M., Tomkiel, C. A., Trentalange, S., Tribble, R. E., Tribedy, P., Tripathy, S. K., Tsai, O. D., Tu, Z., Ullrich, T., Underwood, D. G., Upsal, I., Van Buren, G., Vanek, J., Vasiliev, A. N., Vassiliev, I., Videbæk, F., Vokal, S., Voloshin, S. A., Wang, F., Wang, G., Wang, J. S., Wang, P., Wang, Y., Wang, Z., Webb, J. C., Weidenkaff, P. C., Wen, L., Westfall, G. D., Wieman, H., Wissink, S. W., Witt, R., Wu, Y., Xiao, Z. G., Xie, G., Xie, W., Xu, H., Xu, N., Xu, Q. H., Xu, Y. F., Xu, Y., Xu, Z., Yang, C., Yang, Q., Yang, S., Yang, Y., Yang, Z., Ye, Z., Yi, L., Yip, K., Zbroszczyk, H., Zha, W., Zhang, D., Zhang, S., Zhang, X. P., Zhang, Y., Zhang, Z. J., Zhang, Z., Zhao, J., Zhong, C., Zhou, C., Zhu, X., Zhu, Z., Zurek, M., and Zyzak, M.

Subjects
High Energy Physics - Experiment
Abstract

In this letter, measurements of the shared momentum fraction ($z_{\rm{g}}$) and the groomed jet radius ($R_{\rm{g}}$), as defined in the SoftDrop algorihm, are reported in \pp collisions at $\sqrt{s} = 200$ GeV collected by the STAR experiment. These substructure observables are differentially measured for jets of varying resolution parameters from $R = 0.2 - 0.6$ in the transverse momentum range $15 < p_{\rm{T, jet}} < 60$ GeV$/c$. These studies show that, in the $p_{\rm{T, jet}}$ range accessible at $\sqrt{s} = 200$ GeV and with increasing jet resolution parameter and jet transverse momentum, the $z_{\rm{g}}$ distribution asymptotically converges to the DGLAP splitting kernel for a quark radiating a gluon. The groomed jet radius measurements reflect a momentum-dependent narrowing of the jet structure for jets of a given resolution parameter, i.e., the larger the $p_{\rm{T, jet}}$, the narrower the first splitting. For the first time, these fully corrected measurements are compared to Monte Carlo generators with leading order QCD matrix elements and leading log in the parton shower, and to state-of-the-art theoretical calculations at next-to-leading-log accuracy. We observe that PYTHIA 6 with parameters tuned to reproduce RHIC measurements is able to quantitatively describe data, whereas PYTHIA 8 and HERWIG 7, tuned to reproduce LHC data, are unable to provide a simultaneous description of both $z_{\rm{g}}$ and $R_{\rm{g}}$, resulting in opportunities for fine parameter tuning of these models for \pp collisions at RHIC energies. We also find that the theoretical calculations without non-perturbative corrections are able to qualitatively describe the trend in data for jets of large resolution parameters at high $p_{\rm{T, jet}}$, but fail at small jet resolution parameters and low jet transverse momenta., Comment: published version. see journal website for supplemental material

Published
2020
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18. Beam energy dependence of net-$\Lambda$ fluctuations measured by the STAR experiment at RHIC

Author

STAR Collaboration, Adam, J., Adamczyk, L., Adams, J. R., Adkins, J. K., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alekseev, I., Anderson, D. M., Aparin, A., Aschenauer, E. C., Ashraf, M. U., Atetalla, F. G., Attri, A., Averichev, G. S., Bairathi, V., Barish, K., Behera, A., Bellwied, R., Bhasin, A., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Brandenburg, J. D., Brandin, A. V., Butterworth, J., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Chakaberia, I., Chaloupka, P., Chan, B. K., Chang, F-H., Chang, Z., Chankova-Bunzarova, N., Chatterjee, A., Chen, D., Chen, J. H., Chen, X., Chen, Z., Cheng, J., Cherney, M., Chevalier, M., Choudhury, S., Christie, W., Crawford, H. J., Csanád, M., Daugherity, M., Dedovich, T. G., Deppner, I. M., Derevschikov, A. A., Didenko, L., Dong, X., Drachenberg, J. L., Dunlop, J. C., Edmonds, T., Elsey, N., Engelage, J., Eppley, G., Esha, R., Esumi, S., Evdokimov, O., Ewigleben, A., Eyser, O., Fatemi, R., Fazio, S., Federic, P., Fedorisin, J., Feng, C. J., Feng, Y., Filip, P., Finch, E., Fisyak, Y., Francisco, A., Fulek, L., Gagliardi, C. A., Galatyuk, T., Geurts, F., Gibson, A., Gopal, K., Grosnick, D., Guryn, W., Hamad, A. I., Hamed, A., Harris, J. W., He, S., He, W., He, X., Heppelmann, S., Herrmann, N., Hoffman, E., Holub, L., Hong, Y., Horvat, S., Hu, Y., Huang, H. Z., Huang, S. L., Huang, T., Huang, X., Humanic, T. J., Huo, P., Igo, G., Isenhower, D., Jacobs, W. W., Jena, C., Jentsch, A., JI, Y., Jia, J., Jiang, K., Jowzaee, S., Ju, X., Judd, E. G., Kabana, S., Kabir, M. L., Kagamaster, S., Kalinkin, D., Kang, K., Kapukchyan, D., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kelsey, M., Khyzhniak, Y. V., Kikoła, D. P., Kim, C., Kimelman, B., Kincses, D., Kinghorn, T. A., Kisel, I., Kiselev, A., Kisiel, A., Kocan, M., Kochenda, L., Kosarzewski, L. K., Kramarik, L., Kravtsov, P., Krueger, K., Mudiyanselage, N. Kulathunga, Kumar, L., Elayavalli, R. Kunnawalkam, Kwasizur, J. H., Lacey, R., Lan, S., Landgraf, J. M., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Leung, Y. H., Li, C., Li, W., Li, X., Li, Y., Liang, Y., Licenik, R., Lin, T., Lin, Y., Lisa, M. A., Liu, F., Liu, H., Liu, P., Liu, T., Liu, X., Liu, Y., Liu, Z., Ljubicic, T., Llope, W. J., Longacre, R. S., Lukow, N. S., Luo, S., Luo, X., Ma, G. L., Ma, L., Ma, R., Ma, Y. G., Magdy, N., Majka, R., Mallick, D., Margetis, S., Markert, C., Matis, H. S., Mazer, J. A., Minaev, N. G., Mioduszewski, S., Mohanty, B., Mooney, I., Moravcova, Z., Morozov, D. A., Nagy, M., Nam, J. D., Nasim, Md., Nayak, K., Neff, D., Nelson, J. M., Nemes, D. B., Nie, M., Nigmatkulov, G., Niida, T., Nogach, L. V., Nonaka, T., Odyniec, G., Ogawa, A., Oh, S., Okorokov, V. A., Page, B. S., Pak, R., Pandav, A., Panebratsev, Y., Pawlik, B., Pawlowska, D., Pei, H., Perkins, C., Pinsky, L., Pintér, R. L., Pluta, J., Porter, J., Posik, M., Pruthi, N. K., Przybycien, M., Putschke, J., Qiu, H., Quintero, A., Radhakrishnan, S. K., Ramachandran, S., Ray, R. L., Reed, R., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ruan, L., Rusnak, J., Sahoo, N. R., Sako, H., Salur, S., Sandweiss, J., Sato, S., Schmidke, W. B., Schmitz, N., Schweid, B. R., Seck, F., Seger, J., Sergeeva, M., Seto, R., Seyboth, P., Shah, N., Shahaliev, E., Shanmuganathan, P. V., Shao, M., Shen, F., Shen, W. Q., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Sikora, R., Simko, M., Singh, J., Singha, S., Smirnov, N., Solyst, W., Sorensen, P., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Stefaniak, M., Stewart, D. J., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Sumbera, M., Summa, B., Sun, X. M., Sun, Y., Surrow, B., Svirida, D. N., Szymanski, P., Tang, A. H., Tang, Z., Taranenko, A., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Tlusty, D., Tokarev, M., Tomkiel, C. A., Trentalange, S., Tribble, R. E., Tribedy, P., Tripathy, S. K., Tsai, O. D., Tu, Z., Ullrich, T., Underwood, D. G., Upsal, I., Van Buren, G., Vanek, J., Vasiliev, A. N., Vassiliev, I., Videbæk, F., Vokal, S., Voloshin, S. A., Wang, F., Wang, G., Wang, J. S., Wang, P., Wang, Y., Wang, Z., Webb, J. C., Weidenkaff, P. C., Wen, L., Westfall, G. D., Wieman, H., Wissink, S. W., Witt, R., Wu, Y., Xiao, Z. G., Xie, G., Xie, W., Xu, H., Xu, N., Xu, Q. H., Xu, Y. F., Xu, Y., Xu, Z., Yang, C., Yang, Q., Yang, S., Yang, Y., Yang, Z., Ye, Z., Yi, L., Yip, K., Zbroszczyk, H., Zha, W., Zhang, D., Zhang, S., Zhang, X. P., Zhang, Y., Zhang, Z. J., Zhang, Z., Zhao, J., Zhong, C., Zhou, C., Zhu, X., Zhu, Z., Zurek, M., and Zyzak, M.

Subjects
Nuclear Experiment, High Energy Physics - Experiment, High Energy Physics - Phenomenology, Nuclear Theory
Abstract

The measurements of particle multiplicity distributions have generated considerable interest in understanding the fluctuations of conserved quantum numbers in the Quantum Chromodynamics (QCD) hadronization regime, in particular near a possible critical point and near the chemical freeze-out. We report the measurement of efficiency and centrality bin width corrected cumulant ratios ($C_{2}/C_{1}$, $C_{3}/C_{2}$) of net-$\Lambda$ distributions, in the context of both strangeness and baryon number conservation, as a function of collision energy, centrality and rapidity. The results are for Au + Au collisions at five beam energies ($\sqrt{s_{NN}}$ = 19.6, 27, 39, 62.4 and 200 GeV) recorded with the Solenoidal Tracker at RHIC (STAR). We compare our results to the Poisson and negative binomial (NBD) expectations, as well as to Ultra-relativistic Quantum Molecular Dynamics (UrQMD) and Hadron Resonance Gas (HRG) model predictions. Both NBD and Poisson baselines agree with data within the statistical and systematic uncertainties. The ratios of the measured cumulants show no features of critical fluctuations. The chemical freeze-out temperatures extracted from a recent HRG calculation, which was successfully used to describe the net-proton, net-kaon and net-charge data, indicate $\Lambda$ freeze-out conditions similar to those of kaons. However, large deviations are found when comparing to temperatures obtained from net-proton fluctuations. The net-$\Lambda$ cumulants show a weak, but finite, dependence on the rapidity coverage in the acceptance of the detector, which can be attributed to quantum number conservation., Comment: 12 pages, 9 figures, 3 tables, submitted to Phys.Rev.C

Published
2020
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19. Non-monotonic energy dependence of net-proton number fluctuations

Author

STAR Collaboration, Adam, J., Adamczyk, L., Adams, J. R., Adkins, J. K., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alekseev, I., Anderson, D. M., Aparin, A., Aschenauer, E. C., Ashraf, M. U., Atetalla, F. G., Attri, A., Averichev, G. S., Bairathi, V., Barish, K., Behera, A., Bellwied, R., Bhasin, A., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Brandenburg, J. D., Brandin, A. V., Butterworth, J., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Chakaberia, I., Chaloupka, P., Chan, B. K., Chang, F-H., Chang, Z., Chankova-Bunzarova, N., Chatterjee, A., Chen, D., Chen, J. H., Chen, X., Chen, Z., Cheng, J., Cherney, M., Chevalier, M., Choudhury, S., Christie, W., Crawford, H. J., Csanád, M., Daugherity, M., Dedovich, T. G., Deppner, I. M., Derevschikov, A. A., Didenko, L., Dong, X., Drachenberg, J. L., Dunlop, J. C., Edmonds, T., Elsey, N., Engelage, J., Eppley, G., Esha, R., Esumi, S., Evdokimov, O., Ewigleben, A., Eyser, O., Fatemi, R., Fazio, S., Federic, P., Fedorisin, J., Feng, C. J., Feng, Y., Filip, P., Finch, E., Fisyak, Y., Francisco, A., Fulek, L., Gagliardi, C. A., Galatyuk, T., Geurts, F., Gibson, A., Gopal, K., Grosnick, D., Guryn, W., Hamad, A. I., Hamed, A., Harris, J. W., He, S., He, W., He, X., Heppelmann, S., Herrmann, N., Hoffman, E., Holub, L., Hong, Y., Horvat, S., Hu, Y., Huang, H. Z., Huang, S. L., Huang, T., Huang, X., Humanic, T. J., Huo, P., Igo, G., Isenhower, D., Jacobs, W. W., Jena, C., Jentsch, A., JI, Y., Jia, J., Jiang, K., Jowzaee, S., Ju, X., Judd, E. G., Kabana, S., Kabir, M. L., Kagamaster, S., Kalinkin, D., Kang, K., Kapukchyan, D., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kelsey, M., Khyzhniak, Y. V., Kikoła, D. P., Kim, C., Kimelman, B., Kincses, D., Kinghorn, T. A., Kisel, I., Kiselev, A., Kisiel, A., Kocan, M., Kochenda, L., Kosarzewski, L. K., Kramarik, L., Kravtsov, P., Krueger, K., Mudiyanselage, N. Kulathunga, Kumar, L., Elayavalli, R. Kunnawalkam, Kwasizur, J. H., Lacey, R., Lan, S., Landgraf, J. M., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Leung, Y. H., Li, C., Li, W., Li, X., Li, Y., Liang, Y., Licenik, R., Lin, T., Lin, Y., Lisa, M. A., Liu, F., Liu, H., Liu, P., Liu, T., Liu, X., Liu, Y., Liu, Z., Ljubicic, T., Llope, W. J., Longacre, R. S., Lukow, N. S., Luo, S., Luo, X., Ma, G. L., Ma, L., Ma, R., Ma, Y. G., Magdy, N., Majka, R., Mallick, D., Margetis, S., Markert, C., Matis, H. S., Mazer, J. A., Minaev, N. G., Mioduszewski, S., Mohanty, B., Mooney, I., Moravcova, Z., Morozov, D. A., Nagy, M., Nam, J. D., Nasim, Md., Nayak, K., Neff, D., Nelson, J. M., Nemes, D. B., Nie, M., Nigmatkulov, G., Niida, T., Nogach, L. V., Nonaka, T., Odyniec, G., Ogawa, A., Oh, S., Okorokov, V. A., Page, B. S., Pak, R., Pandav, A., Panebratsev, Y., Pawlik, B., Pawlowska, D., Pei, H., Perkins, C., Pinsky, L., Pintér, R. L., Pluta, J., Porter, J., Posik, M., Pruthi, N. K., Przybycien, M., Putschke, J., Qiu, H., Quintero, A., Radhakrishnan, S. K., Ramachandran, S., Ray, R. L., Reed, R., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ruan, L., Rusnak, J., Sahoo, N. R., Sako, H., Salur, S., Sandweiss, J., Sato, S., Schmidke, W. B., Schmitz, N., Schweid, B. R., Seck, F., Seger, J., Sergeeva, M., Seto, R., Seyboth, P., Shah, N., Shahaliev, E., Shanmuganathan, P. V., Shao, M., Shen, F., Shen, W. Q., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Sikora, R., Simko, M., Singh, J., Singha, S., Smirnov, N., Solyst, W., Sorensen, P., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Stefaniak, M., Stewart, D. J., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Sumbera, M., Summa, B., Sun, X. M., Sun, Y., Surrow, B., Svirida, D. N., Szymanski, P., Tang, A. H., Tang, Z., Taranenko, A., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Tlusty, D., Tokarev, M., Tomkiel, C. A., Trentalange, S., Tribble, R. E., Tribedy, P., Tripathy, S. K., Tsai, O. D., Tu, Z., Ullrich, T., Underwood, D. G., Upsal, I., Van Buren, G., Vanek, J., Vasiliev, A. N., Vassiliev, I., Videbæk, F., Vokal, S., Voloshin, S. A., Wang, F., Wang, G., Wang, J. S., Wang, P., Wang, Y., Wang, Z., Webb, J. C., Weidenkaff, P. C., Wen, L., Westfall, G. D., Wieman, H., Wissink, S. W., Witt, R., Wu, Y., Xiao, Z. G., Xie, G., Xie, W., Xu, H., Xu, N., Xu, Q. H., Xu, Y. F., Xu, Y., Xu, Z., Yang, C., Yang, Q., Yang, S., Yang, Y., Yang, Z., Ye, Z., Yi, L., Yip, K., Zbroszczyk, H., Zha, W., Zhang, D., Zhang, S., Zhang, X. P., Zhang, Y., Zhang, Z. J., Zhang, Z., Zhao, J., Zhong, C., Zhou, C., Zhu, X., Zhu, Z., Zurek, M., and Zyzak, M.

Subjects
Nuclear Experiment, High Energy Physics - Experiment, High Energy Physics - Phenomenology, Nuclear Theory
Abstract

Non-monotonic variation with collision energy ($\sqrt{s_{\rm NN}}$) of the moments of the net-baryon number distribution in heavy-ion collisions, related to the correlation length and the susceptibilities of the system, is suggested as a signature for the Quantum Chromodynamics (QCD) critical point. We report the first evidence of a non-monotonic variation in kurtosis times variance of the net-proton number (proxy for net-baryon number) distribution as a function of \rootsnn with 3.1$\sigma$ significance, for head-on (central) gold-on-gold (Au+Au) collisions measured using the STAR detector at RHIC. Data in non-central Au+Au collisions and models of heavy-ion collisions without a critical point show a monotonic variation as a function of $\sqrt{s_{\rm NN}}$., Comment: 12 Pages, 9 Figures and 5 Tables (published version)

Published
2020
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20. Underlying event measurements in $p$+$p$ collisions at $\sqrt{s}= 200 $ GeV at RHIC

Author

STAR Collaboration, Adam, J., Adamczyk, L., Adams, J. R., Adkins, J. K., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alekseev, I., Anderson, D. M., Aparin, A., Aschenauer, E. C., Ashraf, M. U., Atetalla, F. G., Attri, A., Averichev, G. S., Bairathi, V., Barish, K., Behera, A., Bellwied, R., Bhasin, A., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Brandenburg, J. D., Brandin, A. V., Butterworth, J., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Chakaberia, I., Chaloupka, P., Chan, B. K., Chang, F-H., Chang, Z., Chankova-Bunzarova, N., Chatterjee, A., Chen, D., Chen, J. H., Chen, X., Chen, Z., Cheng, J., Cherney, M., Chevalier, M., Choudhury, S., Christie, W., Crawford, H. J., Csanád, M., Daugherity, M., Dedovich, T. G., Deppner, I. M., Derevschikov, A. A., Didenko, L., Dong, X., Drachenberg, J. L., Dunlop, J. C., Edmonds, T., Elsey, N., Engelage, J., Eppley, G., Esha, R., Esumi, S., Evdokimov, O., Ewigleben, A., Eyser, O., Fatemi, R., Fazio, S., Federic, P., Fedorisin, J., Feng, C. J., Feng, Y., Filip, P., Finch, E., Fisyak, Y., Francisco, A., Fulek, L., Gagliardi, C. A., Galatyuk, T., Geurts, F., Gibson, A., Gopal, K., Grosnick, D., Guryn, W., Hamad, A. I., Hamed, A., Harris, J. W., He, S., He, W., He, X., Heppelmann, S., Herrmann, N., Hoffman, E., Holub, L., Hong, Y., Horvat, S., Hu, Y., Huang, H. Z., Huang, S. L., Huang, T., Huang, X., Humanic, T. J., Huo, P., Igo, G., Isenhower, D., Jacobs, W. W., Jena, C., Jentsch, A., JI, Y., Jia, J., Jiang, K., Jowzaee, S., Ju, X., Judd, E. G., Kabana, S., Kabir, M. L., Kagamaster, S., Kalinkin, D., Kang, K., Kapukchyan, D., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kelsey, M., Khyzhniak, Y. V., Kikoła, D. P., Kim, C., Kimelman, B., Kincses, D., Kinghorn, T. A., Kisel, I., Kiselev, A., Kisiel, A., Kocan, M., Kochenda, L., Kosarzewski, L. K., Kramarik, L., Kravtsov, P., Krueger, K., Mudiyanselage, N. Kulathunga, Kumar, L., Elayavalli, R. Kunnawalkam, Kwasizur, J. H., Lacey, R., Lan, S., Landgraf, J. M., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Leung, Y. H., Li, C., Li, W., Li, X., Li, Y., Liang, Y., Licenik, R., Lin, T., Lin, Y., Lisa, M. A., Liu, F., Liu, H., Liu, P., Liu, T., Liu, X., Liu, Y., Liu, Z., Ljubicic, T., Llope, W. J., Longacre, R. S., Lukow, N. S., Luo, S., Luo, X., Ma, G. L., Ma, L., Ma, R., Ma, Y. G., Magdy, N., Majka, R., Mallick, D., Margetis, S., Markert, C., Matis, H. S., Mazer, J. A., Minaev, N. G., Mioduszewski, S., Mohanty, B., Mooney, I., Moravcova, Z., Morozov, D. A., Nagy, M., Nam, J. D., Nasim, Md., Nayak, K., Neff, D., Nelson, J. M., Nemes, D. B., Nie, M., Nigmatkulov, G., Niida, T., Nogach, L. V., Nonaka, T., Odyniec, G., Ogawa, A., Oh, S., Okorokov, V. A., Page, B. S., Pak, R., Pandav, A., Panebratsev, Y., Pawlik, B., Pawlowska, D., Pei, H., Perkins, C., Pinsky, L., Pintér, R. L., Pluta, J., Porter, J., Posik, M., Pruthi, N. K., Przybycien, M., Putschke, J., Qiu, H., Quintero, A., Radhakrishnan, S. K., Ramachandran, S., Ray, R. L., Reed, R., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ruan, L., Rusnak, J., Sahoo, N. R., Sako, H., Salur, S., Sandweiss, J., Sato, S., Schmidke, W. B., Schmitz, N., Schweid, B. R., Seck, F., Seger, J., Sergeeva, M., Seto, R., Seyboth, P., Shah, N., Shahaliev, E., Shanmuganathan, P. V., Shao, M., Shen, F., Shen, W. Q., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Sikora, R., Simko, M., Singh, J., Singha, S., Smirnov, N., Solyst, W., Sorensen, P., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Stefaniak, M., Stewart, D. J., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Sumbera, M., Summa, B., Sun, X. M., Sun, Y., Surrow, B., Svirida, D. N., Szymanski, P., Tang, A. H., Tang, Z., Taranenko, A., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Tlusty, D., Tokarev, M., Tomkiel, C. A., Trentalange, S., Tribble, R. E., Tribedy, P., Tripathy, S. K., Tsai, O. D., Tu, Z., Ullrich, T., Underwood, D. G., Upsal, I., Van Buren, G., Vanek, J., Vasiliev, A. N., Vassiliev, I., Videbæk, F., Vokal, S., Voloshin, S. A., Wang, F., Wang, G., Wang, J. S., Wang, P., Wang, Y., Wang, Z., Webb, J. C., Weidenkaff, P. C., Wen, L., Westfall, G. D., Wieman, H., Wissink, S. W., Witt, R., Wu, Y., Xiao, Z. G., Xie, G., Xie, W., Xu, H., Xu, N., Xu, Q. H., Xu, Y. F., Xu, Y., Xu, Z., Yang, C., Yang, Q., Yang, S., Yang, Y., Yang, Z., Ye, Z., Yi, L., Yip, K., Zbroszczyk, H., Zha, W., Zhang, D., Zhang, S., Zhang, X. P., Zhang, Y., Zhang, Z. J., Zhang, Z., Zhao, J., Zhong, C., Zhou, C., Zhu, X., Zhu, Z., Zurek, M., and Zyzak, M.

Subjects
Nuclear Experiment, High Energy Physics - Experiment
Abstract

Particle production sensitive to non-factorizable and non-perturbative processes that contribute to the underlying event associated with a high transverse momentum ($p_{T}$) jet in proton+proton collisions at $\sqrt{s}$=200 GeV is studied with the STAR detector. Each event is divided into three regions based on the azimuthal angle with respect to the highest-$p_{T}$ jet direction: in the leading jet direction ("Toward"), opposite to the leading jet ("Away"), and perpendicular to the leading jet ("Transverse"). In the Transverse region, the average charged particle density is found to be between 0.4 and 0.6 and the mean transverse momentum, $\langle p_{T}\rangle$, between 0.5-0.7 GeV/$c$ for particles with $p_{T}$$>$0.2 GeV/$c$ at mid-pseudorapidity ($|\eta|$$<$1) and jet $p_{T}$$>$15 GeV/$c$. Both average particle density and $\langle p_{T}\rangle$ depend weakly on the leading jet $p_{T}$. Closer inspection of the Transverse region hints that contributions to the underlying event from initial- and final-state radiation are significantly smaller in these collisions than at the higher energies, up to 13 TeV, recorded at the LHC. Underlying event measurements associated with a high-$p_{T}$ jet will contribute to our understanding of QCD processes at hard and soft scales at RHIC energies, as well as provide constraints to modeling of underlying event dynamics.

Published
2019
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21. Optimization of Tape Casting for Fabrication of Li6.25Al0.25La3Zr2O12Sheets

Author

Jonson, RA, Yi, E, Shen, F, and Tucker, MC

Subjects
Energy, Physical Chemistry (incl. Structural), Chemical Engineering, Resources Engineering and Extractive Metallurgy
Abstract

Tape casting is an attractive technology for the scalable manufacturing of thin lithium garnet electrolyte (LLZO) layers for solid state battery applications. Processing of LLZO is complicated by many factors including lithium volatilization, abnormal grain growth, and phase instability, which are exacerbated by high surface area to volume ratios. In this work a sintering protocol for commercially available Li6.25Al0.25La3Zr2O12 (Al-LLZO) powder was developed that requires no mother-powder covering or externally applied pressure. MgO was investigated as a sintering additive to improve density and ionic conductivity of the Al-LLZO sheets and produce a fine-grained microstructure. Al-LLZO sheets with 5 wt % MgO had densities of >90% and ionic conductivity > 2 × 10-4 S/cm. The optimized ceramic composition and sintering protocol were used to compare several tape casting binder systems. A "green"water-based system using methylcellulose as a binder was developed with green and final properties comparable to those obtained with solvent-based systems.

Published
2021

22. Scaleup and manufacturability of symmetric-structured metal-supported solid oxide fuel cells

Author

Dogdibegovic, E, Cheng, Y, Shen, F, Wang, R, Hu, B, and Tucker, MC

Subjects
Metal-supported, SOFC, Scale up, Infiltration, Energy, Chemical Sciences, Engineering
Abstract

Metal-supported solid oxide fuel cells with symmetric architecture, having metal supports on both sides of the cell, are scaled up from button cell size to large 50 cm2 active area cell size. The cells remain flat after sintering assisted by the symmetric structure. Equivalent performance is achieved for button cells and large cells, and thermal cycling and redox cycling tolerance are demonstrated for the large cells. The catalyst infiltration process is improved to enable high-throughput manufacturing. The cumbersome lab-scale molten nitrate infiltration process is replaced with a room-temperature process in which a shelf-stable aqueous solution of nitrate salts is applied to the cell by spraying, painting, or other scalable techniques. A fast-ramp thermal conversion of the nitrate salts to the final oxide catalyst composition is implemented, allowing many infiltration cycles to be accomplished in a single work shift. Increasing the number of infiltration cycles from 5 to 10 led to an increase in peak power density from approximately 0.3 to 0.52 W cm−2.

Published
2021

23. Measurement of D$^0$-meson + hadron two-dimensional angular correlations in Au+Au collisions at $\sqrt{s_{\rm NN}} = $ 200 GeV

Author

STAR Collaboration, Adam, J., Adamczyk, L., Adams, J. R., Adkins, J. K., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alekseev, I., Anderson, D. M., Aparin, A., Aschenauer, E. C., Ashraf, M. U., Atetalla, F. G., Attri, A., Averichev, G. S., Bairathi, V., Barish, K., Behera, A., Bellwied, R., Bhasin, A., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Brandenburg, J. D., Brandin, A. V., Butterworth, J., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Chakaberia, I., Chaloupka, P., Chan, B. K., Chang, F-H., Chang, Z., Chankova-Bunzarova, N., Chatterjee, A., Chen, D., Chen, J. H., Chen, X., Chen, Z., Cheng, J., Cherney, M., Chevalier, M., Choudhury, S., Christie, W., Chu, X., Crawford, H. J., Csanád, M., Daugherity, M., Dedovich, T. G., Deppner, I. M., Derevschikov, A. A., Didenko, L., Dong, X., Drachenberg, J. L., Dunlop, J. C., Edmonds, T., Elsey, N., Engelage, J., Eppley, G., Esha, R., Esumi, S., Evdokimov, O., Ewigleben, J., Eyser, O., Fatemi, R., Fazio, S., Federic, P., Fedorisin, J., Feng, C. J., Feng, Y., Filip, P., Finch, E., Fisyak, Y., Francisco, A., Fulek, L., Gagliardi, C. A., Galatyuk, T., Geurts, F., Gibson, A., Gopal, K., Grosnick, D., Guryn, W., Hamad, A. I., Hamed, A., Harris, J. W., He, W., He, X., Heppelmann, S., Herrmann, N., Hoffman, E., Holub, L., Hong, Y., Horvat, S., Hu, Y., Huang, H. Z., Huang, S. L., Huang, T., Huang, X., Humanic, T. J., Huo, P., Igo, G., Isenhower, D., Jacobs, W. W., Jena, C., Jentsch, A., JI, Y., Jia, J., Jiang, K., Jowzaee, S., Ju, X., Judd, E. G., Kabana, S., Kabir, M. L., Kagamaster, S., Kalinkin, D., Kang, K., Kapukchyan, D., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kelsey, M., Khyzhniak, Y. V., Kikoła, D. P., Kim, C., Kimelman, B., Kincses, D., Kinghorn, T. A., Kisel, I., Kiselev, A., Kisiel, A., Kocan, M., Kochenda, L., Kosarzewski, L. K., Kramarik, L., Kravtsov, P., Krueger, K., Mudiyanselage, N. Kulathunga, Kumar, L., Elayavalli, R. Kunnawalkam, Kwasizur, J. H., Lacey, R., Lan, S., Landgraf, J. M., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Leung, Y. H., Li, C., Li, W., Li, X., Li, Y., Liang, Y., Licenik, R., Lin, T., Lin, Y., Lisa, M. A., Liu, F., Liu, H., Liu, P., Liu, T., Liu, X., Liu, Y., Liu, Z., Ljubicic, T., Llope, W. J., Longacre, R. S., Lukow, N. S., Luo, S., Luo, X., Ma, G. L., Ma, L., Ma, R., Ma, Y. G., Magdy, N., Majka, R., Mallick, D., Margetis, S., Markert, C., Matis, H. S., Mazer, J. A., Minaev, N. G., Mioduszewski, S., Mohanty, B., Mooney, I., Moravcova, Z., Morozov, D. A., Nagy, M., Nam, J. D., Nasim, Md., Nayak, K., Neff, D., Nelson, J. M., Nemes, D. B., Nie, M., Nigmatkulov, G., Niida, T., Nogach, L. V., Nonaka, T., Odyniec, G., Ogawa, A., Oh, S., Okorokov, V. A., Page, B. S., Pak, R., Pandav, A., Panebratsev, Y., Pawlik, B., Pawlowska, D., Pei, H., Perkins, C., Pinsky, L., Pintér, R. L., Pluta, J., Porter, J., Posik, M., Pruthi, N. K., Przybycien, M., Putschke, J., Qiu, H., Quintero, A., Radhakrishnan, S. K., Ramachandran, S., Ray, R. L., Reed, R., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ruan, L., Rusnak, J., Sahoo, N. R., Sako, H., Salur, S., Sandweiss, J., Sato, S., Schmidke, W. B., Schmitz, N., Schweid, B. R., Seck, F., Seger, J., Sergeeva, M., Seto, R., Seyboth, P., Shah, N., Shahaliev, E., Shanmuganathan, P. V., Shao, M., Shen, F., Shen, W. Q., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Sikora, R., Simko, M., Singh, J., Singha, S., Smirnov, N., Solyst, W., Sorensen, P., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Stefaniak, M., Stewart, D. J., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Sumbera, M., Summa, B., Sun, X. M., Sun, Y., Surrow, B., Svirida, D. N., Szymanski, P., Tang, A. H., Tang, Z., Taranenko, A., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Tlusty, D., Tokarev, M., Tomkiel, C. A., Trentalange, S., Tribble, R. E., Tribedy, P., Tripathy, S. K., Tsai, O. D., Tu, Z., Ullrich, T., Underwood, D. G., Upsal, I., Van Buren, G., Vanek, J., Vasiliev, A. N., Vassiliev, I., Videbæk, F., Vokal, S., Voloshin, S. A., Wang, F., Wang, G., Wang, J. S., Wang, P., Wang, Y., Wang, Z., Webb, J. C., Weidenkaff, P. C., Wen, L., Westfall, G. D., Wieman, H., Wissink, S. W., Witt, R., Wu, Y., Xiao, Z. G., Xie, G., Xie, W., Xu, H., Xu, N., Xu, Q. H., Xu, Y. F., Xu, Y., Xu, Z., Yang, C., Yang, Q., Yang, S., Yang, Y., Yang, Z., Ye, Z., Yi, L., Yip, K., Zbroszczyk, H., Zha, W., Zhang, D., Zhang, S., Zhang, X. P., Zhang, Y., Zhang, Z. J., Zhang, Z., Zhao, J., Zhong, C., Zhou, C., Zhu, X., Zhu, Z., Zurek, M., and Zyzak, M.

Subjects
Nuclear Experiment
Abstract

Open heavy flavor hadrons provide unique probes of the medium produced in ultra-relativistic heavy-ion collisions. Due to their increased mass relative to light-flavor hadrons, long lifetime, and early production in hard-scattering interactions, they provide access to the full evolution of the partonic medium formed in heavy-ion collisions. This paper reports two-dimensional (2D) angular correlations between neutral $D$-mesons and unidentified charged particles produced in minimum-bias Au+Au collisions at $\sqrt{s_{\rm NN}}$ = 200 GeV. $D^0$ and $\bar{D}^0$ mesons are reconstructed via their weak decay to $K^{\mp} \pi^{\pm}$ using the Heavy Flavor Tracker (HFT) in the Solenoidal Tracker at RHIC (STAR) experiment. Correlations on relative pseudorapidity and azimuth $(\Delta\eta,\Delta\phi)$ are presented for peripheral, mid-central and central collisions with $D^0$ transverse momentum from 2 to 10 GeV/$c$. Attention is focused on the 2D peaked correlation structure near the triggered $D^0$-meson, the {\em near-side} (NS) peak, which serves as a proxy for a charm-quark containing jet. The correlated NS yield of charged particles per $D^0$-meson and the 2D widths of the NS peak increase significantly from peripheral to central collisions. These results are compared with similar correlations using unidentified charged particles, consisting primarily of light-flavor hadrons, at similar trigger particle momenta. Similar per-trigger yields and widths of the NS correlation peak are observed. The present results provide additional evidence that $D^0$-mesons undergo significant interactions with the medium formed in heavy-ion collision and show, for the first time, significant centrality evolution of the NS 2D peak in the correlations of particles associated with a heavy-flavor hadron produced in these collisions.

Published
2019
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24. Methods for a blind analysis of isobar data collected by the STAR collaboration

Author

STAR Collaboration, Adam, J., Adamczyk, L., Adams, J. R., Adkins, J. K., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alekseev, I., Anderson, D. M., Aparin, A., Aschenauer, E. C., Ashraf, M. U., Atetalla, F. G., Attri, A., Averichev, G. S., Bairathi, V., Barish, K., Behera, A., Bellwied, R., Bhasin, A., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Brandenburg, J. D., Brandin, A. V., Butterworth, J., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Chakaberia, I., Chaloupka, P., Chan, B. K., Chang, F-H., Chang, Z., Chankova-Bunzarova, N., Chatterjee, A., Chen, D., Chen, J. H., Chen, X., Chen, Z., Cheng, J., Cherney, M., Chevalier, M., Choudhury, S., Christie, W., Crawford, H. J., Csanád, M., Daugherity, M., Dedovich, T. G., Deppner, I. M., Derevschikov, A. A., Didenko, L., Dong, X., Drachenberg, J. L., Dunlop, J. C., Edmonds, T., Elsey, N., Engelage, J., Eppley, G., Esha, R., Esumi, S., Evdokimov, O., Ewigleben, J., Eyser, O., Fatemi, R., Fazio, S., Federic, P., Fedorisin, J., Feng, C. J., Feng, Y., Filip, P., Finch, E., Fisyak, Y., Francisco, A., Fulek, L., Gagliardi, C. A., Galatyuk, T., Geurts, F., Gibson, A., Gopal, K., Grosnick, D., Guryn, W., Hamad, A. I., Hamed, A., Harris, J. W., He, W., He, X., Heppelmann, S., Herrmann, N., Hoffman, E., Holub, L., Hong, Y., Horvat, S., Hu, Y., Huang, H. Z., Huang, S. L., Huang, T., Huang, X., Humanic, T. J., Huo, P., Igo, G., Isenhower, D., Jacobs, W. W., Jena, C., Jentsch, A., JI, Y., Jia, J., Jiang, K., Jowzaee, S., Ju, X., Judd, E. G., Kabana, S., Kabir, M. L., Kagamaster, S., Kalinkin, D., Kang, K., Kapukchyan, D., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kelsey, M., Khyzhniak, Y. V., Kikoła, D. P., Kim, C., Kimelman, B., Kincses, D., Kinghorn, T. A., Kisel, I., Kiselev, A., Kisiel, A., Kocan, M., Kochenda, L., Kosarzewski, L. K., Kramarik, L., Kravtsov, P., Krueger, K., Mudiyanselage, N. Kulathunga, Kumar, L., Elayavalli, R. Kunnawalkam, Kwasizur, J. H., Lacey, R., Lan, S., Landgraf, J. M., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Leung, Y. H., Li, C., Li, W., Li, X., Li, Y., Liang, Y., Licenik, R., Lin, T., Lin, Y., Lisa, M. A., Liu, F., Liu, H., Liu, P., Liu, T., Liu, X., Liu, Y., Liu, Z., Ljubicic, T., Llope, W. J., Longacre, R. S., Lukow, N. S., Luo, S., Luo, X., Ma, G. L., Ma, L., Ma, R., Ma, Y. G., Magdy, N., Majka, R., Mallick, D., Margetis, S., Markert, C., Matis, H. S., Mazer, J. A., Minaev, N. G., Mioduszewski, S., Mohanty, B., Mooney, I., Moravcova, Z., Morozov, D. A., Nagy, M., Nam, J. D., Nasim, Md., Nayak, K., Neff, D., Nelson, J. M., Nemes, D. B., Nie, M., Nigmatkulov, G., Niida, T., Nogach, L. V., Nonaka, T., Odyniec, G., Ogawa, A., Oh, S., Okorokov, V. A., Page, B. S., Pak, R., Pandav, A., Panebratsev, Y., Pawlik, B., Pawlowska, D., Pei, H., Perkins, C., Pinsky, L., Pintér, R. L., Pluta, J., Porter, J., Posik, M., Pruthi, N. K., Przybycien, M., Putschke, J., Qiu, H., Quintero, A., Radhakrishnan, S. K., Ramachandran, S., Ray, R. L., Reed, R., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ruan, L., Rusnak, J., Sahoo, N. R., Sako, H., Salur, S., Sandweiss, J., Sato, S., Schmidke, W. B., Schmitz, N., Schweid, B. R., Seck, F., Seger, J., Sergeeva, M., Seto, R., Seyboth, P., Shah, N., Shahaliev, E., Shanmuganathan, P. V., Shao, M., Shen, F., Shen, W. Q., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Sikora, R., Simko, M., Singh, J., Singha, S., Smirnov, N., Solyst, W., Sorensen, P., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Stefaniak, M., Stewart, D. J., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Sumbera, M., Summa, B., Sun, X. M., Sun, Y., Surrow, B., Svirida, D. N., Szymanski, P., Tang, A. H., Tang, Z., Taranenko, A., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Tlusty, D., Tokarev, M., Tomkiel, C. A., Trentalange, S., Tribble, R. E., Tribedy, P., Tripathy, S. K., Tsai, O. D., Tu, Z., Ullrich, T., Underwood, D. G., Upsal, I., Van Buren, G., Vanek, J., Vasiliev, A. N., Vassiliev, I., Videbæk, F., Vokal, S., Voloshin, S. A., Wang, F., Wang, G., Wang, J. S., Wang, P., Wang, Y., Wang, Z., Webb, J. C., Weidenkaff, P. C., Wen, L., Westfall, G. D., Wieman, H., Wissink, S. W., Witt, R., Wu, Y., Xiao, Z. G., Xie, G., Xie, W., Xu, H., Xu, N., Xu, Q. H., Xu, Y. F., Xu, Y., Xu, Z., Yang, C., Yang, Q., Yang, S., Yang, Y., Yang, Z., Ye, Z., Yi, L., Yip, K., Zbroszczyk, H., Zha, W., Zhang, D., Zhang, S., Zhang, X. P., Zhang, Y., Zhang, Z. J., Zhang, Z., Zhao, J., Zhong, C., Zhou, C., Zhu, X., Zhu, Z., Zurek, M., and Zyzak, M.

Subjects
Nuclear Experiment, High Energy Physics - Experiment
Abstract

In 2018, the STAR collaboration collected data from $_{44}^{96}Ru+_{44}^{96}Ru$ and $_{40}^{96}Zr+_{40}^{96}Zr$ at $\sqrt{s_{NN}}=200$ GeV to search for the presence of the chiral magnetic effect in collisions of nuclei. The isobar collision species alternated frequently between $_{44}^{96}Ru+_{44}^{96}Ru$ and $_{40}^{96}Zr+_{40}^{96}Zr$. In order to conduct blind analyses of studies related to the chiral magnetic effect in these isobar data, STAR developed a three-step blind analysis procedure. Analysts are initially provided a "reference sample" of data, comprised of a mix of events from the two species, the order of which respects time-dependent changes in run conditions. After tuning analysis codes and performing time-dependent quality assurance on the reference sample, analysts are provided a species-blind sample suitable for calculating efficiencies and corrections for individual $\approx30$-minute data-taking runs. For this sample, species-specific information is disguised, but individual output files contain data from a single isobar species. Only run-by-run corrections and code alteration subsequent to these corrections are allowed at this stage. Following these modifications, the "frozen" code is passed over the fully un-blind data, completing the blind analysis. As a check of the feasibility of the blind analysis procedure, analysts completed a "mock data challenge," analyzing data from $Au+Au$ collisions at $\sqrt{s_{NN}}=27$ GeV, collected in 2018. The $Au+Au$ data were prepared in the same manner intended for the isobar blind data. The details of the blind analysis procedure and results from the mock data challenge are presented.

Published
2019

25. First measurement of $\Lambda_c$ baryon production in Au+Au collisions at $\sqrt{s_{\rm NN}}$ = 200 GeV

Author

STAR Collaboration, Adam, J., Adamczyk, L., Adams, J. R., Adkins, J. K., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alekseev, I., Anderson, D. M., Aparin, A., Aschenauer, E. C., Ashraf, M. U., Atetalla, F. G., Attri, A., Averichev, G. S., Bairathi, V., Barish, K., Behera, A., Bellwied, R., Bhasin, A., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Brandenburg, J. D., Brandin, A. V., Butterworth, J., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Chakaberia, I., Chaloupka, P., Chan, B. K., Chang, F-H., Chang, Z., Chankova-Bunzarova, N., Chatterjee, A., Chen, D., Chen, J. H., Chen, X., Chen, Z., Cheng, J., Cherney, M., Chevalier, M., Choudhury, S., Christie, W., Crawford, H. J., Csanád, M., Daugherity, M., Dedovich, T. G., Deppner, I. M., Derevschikov, A. A., Didenko, L., Dong, X., Drachenberg, J. L., Dunlop, J. C., Edmonds, T., Elsey, N., Engelage, J., Eppley, G., Esha, R., Esumi, S., Evdokimov, O., Ewigleben, J., Eyser, O., Fatemi, R., Fazio, S., Federic, P., Fedorisin, J., Feng, C. J., Feng, Y., Filip, P., Finch, E., Fisyak, Y., Francisco, A., Fulek, L., Gagliardi, C. A., Galatyuk, T., Geurts, F., Gibson, A., Gopal, K., Grosnick, D., Guryn, W., Hamad, A. I., Hamed, A., Harris, J. W., He, W., He, X., Heppelmann, S., Herrmann, N., Hoffman, E., Holub, L., Hong, Y., Horvat, S., Hu, Y., Huang, H. Z., Huang, S. L., Huang, T., Huang, X., Humanic, T. J., Huo, P., Igo, G., Isenhower, D., Jacobs, W. W., Jena, C., Jentsch, A., JI, Y., Jia, J., Jiang, K., Jowzaee, S., Ju, X., Judd, E. G., Kabana, S., Kabir, M. L., Kagamaster, S., Kalinkin, D., Kang, K., Kapukchyan, D., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kelsey, M., Khyzhniak, Y. V., Kikoła, D. P., Kim, C., Kimelman, B., Kincses, D., Kinghorn, T. A., Kisel, I., Kiselev, A., Kisiel, A., Kocan, M., Kochenda, L., Kosarzewski, L. K., Kramarik, L., Kravtsov, P., Krueger, K., Mudiyanselage, N. Kulathunga, Kumar, L., Elayavalli, R. Kunnawalkam, Kwasizur, J. H., Lacey, R., Lan, S., Landgraf, J. M., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Leung, Y. H., Li, C., Li, W., Li, X., Li, Y., Liang, Y., Licenik, R., Lin, T., Lin, Y., Lisa, M. A., Liu, F., Liu, H., Liu, P., Liu, T., Liu, X., Liu, Y., Liu, Z., Ljubicic, T., Llope, W. J., Longacre, R. S., Lukow, N. S., Luo, S., Luo, X., Ma, G. L., Ma, L., Ma, R., Ma, Y. G., Magdy, N., Majka, R., Mallick, D., Margetis, S., Markert, C., Matis, H. S., Mazer, J. A., Minaev, N. G., Mioduszewski, S., Mohanty, B., Mooney, I., Moravcova, Z., Morozov, D. A., Nagy, M., Nam, J. D., Nasim, Md., Nayak, K., Neff, D., Nelson, J. M., Nemes, D. B., Nie, M., Nigmatkulov, G., Niida, T., Nogach, L. V., Nonaka, T., Odyniec, G., Ogawa, A., Oh, S., Okorokov, V. A., Page, B. S., Pak, R., Pandav, A., Panebratsev, Y., Pawlik, B., Pawlowska, D., Pei, H., Perkins, C., Pinsky, L., Pintér, R. L., Pluta, J., Porter, J., Posik, M., Pruthi, N. K., Przybycien, M., Putschke, J., Qiu, H., Quintero, A., Radhakrishnan, S. K., Ramachandran, S., Ray, R. L., Reed, R., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ruan, L., Rusnak, J., Sahoo, N. R., Sako, H., Salur, S., Sandweiss, J., Sato, S., Schmidke, W. B., Schmitz, N., Schweid, B. R., Seck, F., Seger, J., Sergeeva, M., Seto, R., Seyboth, P., Shah, N., Shahaliev, E., Shanmuganathan, P. V., Shao, M., Shen, F., Shen, W. Q., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Sikora, R., Simko, M., Singh, J., Singha, S., Smirnov, N., Solyst, W., Sorensen, P., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Stefaniak, M., Stewart, D. J., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Sumbera, M., Summa, B., Sun, X. M., Sun, Y., Surrow, B., Svirida, D. N., Szymanski, P., Tang, A. H., Tang, Z., Taranenko, A., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Tlusty, D., Tokarev, M., Tomkiel, C. A., Trentalange, S., Tribble, R. E., Tribedy, P., Tripathy, S. K., Tsai, O. D., Tu, Z., Ullrich, T., Underwood, D. G., Upsal, I., Van Buren, G., Vanek, J., Vasiliev, A. N., Vassiliev, I., Videbæk, F., Vokal, S., Voloshin, S. A., Wang, F., Wang, G., Wang, J. S., Wang, P., Wang, Y., Wang, Z., Webb, J. C., Weidenkaff, P. C., Wen, L., Westfall, G. D., Wieman, H., Wissink, S. W., Witt, R., Wu, Y., Xiao, Z. G., Xie, G., Xie, W., Xu, H., Xu, N., Xu, Q. H., Xu, Y. F., Xu, Y., Xu, Z., Yang, C., Yang, Q., Yang, S., Yang, Y., Yang, Z., Ye, Z., Yi, L., Yip, K., Zbroszczyk, H., Zha, W., Zhang, D., Zhang, S., Zhang, X. P., Zhang, Y., Zhang, Z. J., Zhang, Z., Zhao, J., Zhong, C., Zhou, C., Zhu, X., Zhu, Z., Zurek, M., and Zyzak, M.

Subjects
Nuclear Experiment, High Energy Physics - Experiment
Abstract

We report on the first measurement of the charmed baryon $\Lambda_c^{\pm}$ production at midrapidity ($|y|$ $<$ 1) in Au+Au collisions at $\sqrt{s_{NN}}$ = 200 GeV collected by the STAR experiment at the Relativistic Heavy Ion Collider. The $\Lambda_c$/$D^0$ (denoting ($\Lambda_c^++\Lambda_c^-$)/($D^0+\bar{D^0}$)) yield ratio is measured to be 1.08 $\pm$ 0.16 (stat.) $\pm$ 0.26 (sys.) in the 0--20% most central Au+Au collisions for the transverse momentum ($p_T$) range 3 $<$ $p_T$ $<$ 6 GeV/$c$. This is significantly larger than the PYTHIA model calculations for $p+p$ collisions. The measured $\Lambda_c$/$D^0$ ratio, as a function of $p_T$ and collision centrality, is comparable to the baryon-to-meson ratios for light and strange hadrons in Au+Au collisions. Model calculations including coalescence hadronization for charmed baryon and meson formation reproduce the features of our measured $\Lambda_c$/$D^0$ ratio., Comment: 5 pages, 3 figures

Published
2019
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26. Bulk Properties of the System Formed in Au+Au Collisions at $\sqrt{s_{\mathrm{NN}}}$ = 14.5 GeV

Author

STAR Collaboration, Adam, J., Adamczyk, L., Adams, J. R., Adkins, J. K., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alekseev, I., Anderson, D. M., Aoyama, R., Aparin, A., Aschenauer, E. C., Ashraf, M. U., Atetalla, F. G., Attri, A., Averichev, G. S., Bairathi, V., Barish, K., Bassill, A. J., Behera, A., Bellwied, R., Bhasin, A., Bhati, A. K., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Brandenburg, J. D., Brandin, A. V., Bryslawskyj, J., Bunzarov, I., Butterworth, J., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Chakaberia, I., Chaloupka, P., Chan, B. K., Chang, F-H., Chang, Z., Chankova-Bunzarova, N., Chatterjee, A., Chattopadhyay, S., Chen, J. H., Chen, X., Cheng, J., Cherney, M., Christie, W., Crawford, H. J., Csanád, M., Das, S., Dedovich, T. G., Deppner, I. M., Derevschikov, A. A., Didenko, L., Dilks, C., Dong, X., Drachenberg, J. L., Dunlop, J. C., Edmonds, T., Elsey, N., Engelage, J., Eppley, G., Esha, R., Esumi, S., Evdokimov, O., Ewigleben, J., Eyser, O., Fatemi, R., Fazio, S., Federic, P., Fedorisin, J., Feng, Y., Filip, P., Finch, E., Fisyak, Y., Fulek, L., Gagliardi, C. A., Galatyuk, T., Geurts, F., Gibson, A., Gopal, K., Grosnick, D., Gupta, A., Guryn, W., Hamad, A. I., Hamed, A., Harris, J. W., He, L., Heppelmann, S., Herrmann, N., Holub, L., Hong, Y., Horvat, S., Huang, B., Huang, H. Z., Huang, S. L., Huang, T., Huang, X., Humanic, T. J., Huo, P., Igo, G., Jacobs, W. W., Jena, C., Jentsch, A., JI, Y., Jia, J., Jiang, K., Jowzaee, S., Ju, X., Judd, E. G., Kabana, S., Kagamaster, S., Kalinkin, D., Kang, K., Kapukchyan, D., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kelsey, M., Khyzhniak, Y. V., Kikoła, D. P., Kim, C., Kinghorn, T. A., Kisel, I., Kisiel, A., Kocan, M., Kochenda, L., Kosarzewski, L. K., Kramarik, L., Kravtsov, P., Krueger, K., Mudiyanselage, N. Kulathunga, Kumar, L., Elayavalli, R. Kunnawalkam, Kwasizur, J. H., Lacey, R., Landgraf, J. M., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Li, C., Li, W., Li, X., Li, Y., Liang, Y., Licenik, R., Lin, T., Lipiec, A., Lisa, M. A., Liu, F., Liu, H., Liu, P., Liu, T., Liu, X., Liu, Y., Liu, Z., Ljubicic, T., Llope, W. J., Lomnitz, M., Longacre, R. S., Luo, S., Luo, X., Ma, G. L., Ma, L., Ma, R., Ma, Y. G., Magdy, N., Majka, R., Mallick, D., Margetis, S., Markert, C., Matis, H. S., Matonoha, O., Mazer, J. A., Meehan, K., Mei, J. C., Minaev, N. G., Mioduszewski, S., Mishra, D., Mohanty, B., Mondal, M. M., Mooney, I., Moravcova, Z., Morozov, D. A., Nasim, Md., Nayak, K., Nelson, J. M., Nemes, D. B., Nie, M., Nigmatkulov, G., Niida, T., Nogach, L. V., Nonaka, T., Odyniec, G., Ogawa, A., Oh, S., Okorokov, V. A., Page, B. S., Pak, R., Panebratsev, Y., Pawlik, B., Pawlowska, D., Pei, H., Perkins, C., Pintér, R. L., Pluta, J., Porter, J., Posik, M., Pruthi, N. K., Przybycien, M., Putschke, J., Quintero, A., Radhakrishnan, S. K., Ramachandran, S., Ray, R. L., Reed, R., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ruan, L., Rusnak, J., Rusnakova, O., Sahoo, N. R., Sahu, P. K., Salur, S., Sandweiss, J., Schambach, J., Schmidke, W. B., Schmitz, N., Schweid, B. R., Seck, F., Seger, J., Sergeeva, M., Seto, R., Seyboth, P., Shah, N., Shahaliev, E., Shanmuganathan, P. V., Shao, M., Shen, F., Shen, W. Q., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Siejka, S., Sikora, R., Simko, M., Singh, J., Singha, S., Smirnov, D., Smirnov, N., Solyst, W., Sorensen, P., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Stefaniak, M., Stewart, D. J., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Sugiura, T., Sumbera, M., Summa, B., Sun, X. M., Sun, Y., Surrow, B., Svirida, D. N., Szymanski, P., Tang, A. H., Tang, Z., Taranenko, A., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Tlusty, D., Tokarev, M., Tomkiel, C. A., Trentalange, S., Tribble, R. E., Tribedy, P., Tripathy, S. K., Tsai, O. D., Tu, B., Tu, Z., Ullrich, T., Underwood, D. G., Upsal, I., Van Buren, G., Vanek, J., Vasiliev, A. N., Vassiliev, I., Videbæk, F., Vokal, S., Voloshin, S. A., Wang, F., Wang, G., Wang, P., Wang, Y., Webb, J. C., Wen, L., Westfall, G. D., Wieman, H., Wissink, S. W., Witt, R., Wu, Y., Xiao, Z. G., Xie, G., Xie, W., Xu, H., Xu, N., Xu, Q. H., Xu, Y. F., Xu, Z., Yang, C., Yang, Q., Yang, S., Yang, Y., Yang, Z., Ye, Z., Yi, L., Yip, K., Zbroszczyk, H., Zha, W., Zhang, D., Zhang, L., Zhang, S., Zhang, X. P., Zhang, Y., Zhang, Z., Zhao, J., Zhong, C., Zhou, C., Zhu, X., Zhu, Z., Zurek, M., and Zyzak, M.

Subjects
Nuclear Experiment, High Energy Physics - Experiment, High Energy Physics - Phenomenology
Abstract

We report systematic measurements of bulk properties of the system created in Au+Au collisions at $\sqrt{s_{\mathrm{NN}}}$ = 14.5 GeV recorded by the STAR detector at the Relativistic Heavy Ion Collider (RHIC).The transverse momentum spectra of $\pi^{\pm}$, $K^{\pm}$ and $p(\bar{p})$ are studied at mid-rapidity ($|y| < 0.1$) for nine centrality intervals. The centrality, transverse momentum ($p_T$),and pseudorapidity ($\eta$) dependence of inclusive charged particle elliptic flow ($v_2$), and rapidity-odd charged particles directed flow ($v_{1}$) results near mid-rapidity are also presented. These measurements are compared with the published results from Au+Au collisions at other energies, and from Pb+Pb collisions at $\sqrt{s_{\mathrm{NN}}}$ = 2.76 TeV. The results at $\sqrt{s_{\mathrm{NN}}}$ = 14.5 GeV show similar behavior as established at other energies and fit well in the energy dependence trend. These results are important as the 14.5 GeV energy fills the gap in $\mu_B$, which is of the order of 100 MeV,between $\sqrt{s_{\mathrm{NN}}}$ =11.5 and 19.6 GeV. Comparisons of the data with UrQMD and AMPT models show poor agreement in general., Comment: 30 pages, 29 figures and 8 tables

Published
2019
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27. Beam-energy dependence of identified two-particle angular correlations in Au+Au collisions at RHIC

Author

STAR Collaboration, Adam, J., Adamczyk, L., Adams, J. R., Adkins, J. K., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alekseev, I., Anderson, D. M., Aparin, A., Aschenauer, E. C., Ashraf, M. U., Atetalla, F. G., Attri, A., Averichev, G. S., Bairathi, V., Barish, K., Behera, A., Bellwied, R., Bhasin, A., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Brandenburg, J. D., Brandin, A. V., Butterworth, J., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Chakaberia, I., Chaloupka, P., Chan, B. K., Chang, F-H., Chang, Z., Chankova-Bunzarova, N., Chatterjee, A., Chen, D., Chen, J. H., Chen, X., Chen, Z., Cheng, J., Cherney, M., Chevalier, M., Choudhury, S., Christie, W., Crawford, H. J., Csanád, M., Daugherity, M., Dedovich, T. G., Deppner, I. M., Derevschikov, A. A., Didenko, L., Dong, X., Drachenberg, J. L., Dunlop, J. C., Edmonds, T., Elsey, N., Engelage, J., Eppley, G., Esha, R., Esumi, S., Evdokimov, O., Ewigleben, J., Eyser, O., Fatemi, R., Fazio, S., Federic, P., Fedorisin, J., Feng, C. J., Feng, Y., Filip, P., Finch, E., Fisyak, Y., Francisco, A., Fulek, L., Gagliardi, C. A., Galatyuk, T., Geurts, F., Gibson, A., Gopal, K., Grosnick, D., Guryn, W., Hamad, A. I., Hamed, A., Harris, J. W., He, W., He, X., Heppelmann, S., Herrmann, N., Hoffman, E., Holub, L., Hong, Y., Horvat, S., Hu, Y., Huang, H. Z., Huang, S. L., Huang, T., Huang, X., Humanic, T. J., Huo, P., Igo, G., Isenhower, D., Jacobs, W. W., Jena, C., Jentsch, A., JI, Y., Jia, J., Jiang, K., Jowzaee, S., Ju, X., Judd, E. G., Kabana, S., Kabir, M. L., Kagamaster, S., Kalinkin, D., Kang, K., Kapukchyan, D., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kelsey, M., Khyzhniak, Y. V., Kikoła, D. P., Kim, C., Kimelman, B., Kincses, D., Kinghorn, T. A., Kisel, I., Kiselev, A., Kisiel, A., Kocan, M., Kochenda, L., Kosarzewski, L. K., Kramarik, L., Kravtsov, P., Krueger, K., Mudiyanselage, N. Kulathunga, Kumar, L., Elayavalli, R. Kunnawalkam, Kwasizur, J. H., Lacey, R., Lan, S., Landgraf, J. M., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Leung, Y. H., Li, C., Li, W., Li, X., Li, Y., Liang, Y., Licenik, R., Lin, T., Lin, Y., Lisa, M. A., Liu, F., Liu, H., Liu, P., Liu, T., Liu, X., Liu, Y., Liu, Z., Ljubicic, T., Llope, W. J., Longacre, R. S., Lukow, N. S., Luo, S., Luo, X., Ma, G. L., Ma, L., Ma, R., Ma, Y. G., Magdy, N., Majka, R., Mallick, D., Margetis, S., Markert, C., Matis, H. S., Mazer, J. A., Minaev, N. G., Mioduszewski, S., Mohanty, B., Mooney, I., Moravcova, Z., Morozov, D. A., Nagy, M., Nam, J. D., Nasim, Md., Nayak, K., Neff, D., Nelson, J. M., Nemes, D. B., Nie, M., Nigmatkulov, G., Niida, T., Nogach, L. V., Nonaka, T., Odyniec, G., Ogawa, A., Oh, S., Okorokov, V. A., Page, B. S., Pak, R., Pandav, A., Panebratsev, Y., Pawlik, B., Pawlowska, D., Pei, H., Perkins, C., Pinsky, L., Pintér, R. L., Pluta, J., Porter, J., Posik, M., Pruthi, N. K., Przybycien, M., Putschke, J., Qiu, H., Quintero, A., Radhakrishnan, S. K., Ramachandran, S., Ray, R. L., Reed, R., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ruan, L., Rusnak, J., Sahoo, N. R., Sako, H., Salur, S., Sandweiss, J., Sato, S., Schmidke, W. B., Schmitz, N., Schweid, B. R., Seck, F., Seger, J., Sergeeva, M., Seto, R., Seyboth, P., Shah, N., Shahaliev, E., Shanmuganathan, P. V., Shao, M., Shen, F., Shen, W. Q., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Sikora, R., Simko, M., Singh, J., Singha, S., Smirnov, N., Solyst, W., Sorensen, P., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Stefaniak, M., Stewart, D. J., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Sumbera, M., Summa, B., Sun, X. M., Sun, Y., Surrow, B., Svirida, D. N., Szymanski, P., Tang, A. H., Tang, Z., Taranenko, A., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Tlusty, D., Tokarev, M., Tomkiel, C. A., Trentalange, S., Tribble, R. E., Tribedy, P., Tripathy, S. K., Tsai, O. D., Tu, Z., Ullrich, T., Underwood, D. G., Upsal, I., Van Buren, G., Vanek, J., Vasiliev, A. N., Vassiliev, I., Videbæk, F., Vokal, S., Voloshin, S. A., Wang, F., Wang, G., Wang, J. S., Wang, P., Wang, Y., Wang, Z., Webb, J. C., Weidenkaff, P. C., Wen, L., Westfall, G. D., Wieman, H., Wissink, S. W., Witt, R., Wu, Y., Xiao, Z. G., Xie, G., Xie, W., Xu, H., Xu, N., Xu, Q. H., Xu, Y. F., Xu, Y., Xu, Z., Yang, C., Yang, Q., Yang, S., Yang, Y., Yang, Z., Ye, Z., Yi, L., Yip, K., Zbroszczyk, H., Zha, W., Zhang, D., Zhang, S., Zhang, X. P., Zhang, Y., Zhang, Z. J., Zhang, Z., Zhao, J., Zhong, C., Zhou, C., Zhu, X., Zhu, Z., Zurek, M., and Zyzak, M.

Subjects
Nuclear Experiment
Abstract

The two-particle angular correlation functions, $R_2$, of pions, kaons, and protons in Au+Au collisions at $\sqrt{s_{NN}}=$ 7.7, 11.5, 14.5, 19.6, 27, 39, 62.4, and 200 GeV were measured by the STAR experiment at RHIC. These correlations were measured for both like-sign and unlike-sign charge combinations and versus the centrality. The correlations of pions and kaons show the expected near-side ({\it i.e.}, at small relative angles) peak resulting from short-range mechanisms. The amplitudes of these short-range correlations decrease with increasing beam energy. However, the proton correlation functions exhibit strong anticorrelations in the near-side region. This behavior is observed for the first time in an A+A collision system. The observed anticorrelation is $p_{T}$-independent and decreases with increasing beam energy and centrality. The experimental results are also compared to the Monte Carlo models UrQMD, Hijing, and AMPT.

Published
2019
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28. Strange hadron production in Au+Au collisions at $\sqrt{s_{_{\mathrm{NN}}}}$ = 7.7, 11.5, 19.6, 27, and 39 GeV

Author

STAR Collaboration, Adam, J., Adamczyk, L., Adams, J. R., Adkins, J. K., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alekseev, I., Anderson, D. M., Aoyama, R., Aparin, A., Arkhipkin, D., Aschenauer, E. C., Ashraf, M. U., Atetalla, F., Attri, A., Averichev, G. S., Bairathi, V., Barish, K., Bassill, A. J., Behera, A., Bellwied, R., Bhasin, A., Bhati, A. K., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Brandenburg, J. D., Brandin, A. V., Bryslawskyj, J., Bunzarov, I., Butterworth, J., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Chakaberia, I., Chaloupka, P., Chan, B. K., Chang, F-H., Chang, Z., Chankova-Bunzarova, N., Chatterjee, A., Chattopadhyay, S., Chen, J. H., Chen, X., Cheng, J., Cherney, M., Christie, W., Crawford, H. J., Csanád, M., Das, S., Dedovich, T. G., Deppner, I. M., Derevschikov, A. A., Didenko, L., Dilks, C., Dong, X., Drachenberg, J. L., Dunlop, J. C., Edmonds, T., Elsey, N., Engelage, J., Eppley, G., Esha, R., Esumi, S., Evdokimov, O., Ewigleben, J., Eyser, O., Fatemi, R., Fazio, S., Federic, P., Fedorisin, J., Feng, Y., Filip, P., Finch, E., Fisyak, Y., Fulek, L., Gagliardi, C. A., Galatyuk, T., Geurts, F., Gibson, A., Gopal, K., Grosnick, D., Gupta, A., Guryn, W., Hamad, A. I., Hamed, A., Harris, J. W., He, L., Heppelmann, S., Herrmann, N., Holub, L., Hong, Y., Horvat, S., Huang, B., Huang, H. Z., Huang, S. L., Huang, T., Huang, X., Humanic, T. J., Huo, P., Igo, G., Jacobs, W. W., Jena, C., Jentsch, A., Ji, Y., Jia, J., Jiang, K., Jowzaee, S., Ju, X., Judd, E. G., Kabana, S., Kagamaster, S., Kalinkin, D., Kang, K., Kapukchyan, D., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kelsey, M., Khyzhniak, Y. V., Kikoła, D. P., Kim, C., Kinghorn, T. A., Kisel, I., Kisiel, A., Kocan, M., Kochenda, L., Kosarzewski, L. K., Kramarik, L., Kravtsov, P., Krueger, K., Mudiyanselage, N. Kulathunga, Kumar, L., Elayavalli, R. Kunnawalkam, Kwasizur, J. H., Lacey, R., Landgraf, J. M., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Li, C., Li, W., Li, X., Li, Y., Liang, Y., Licenik, R., Lin, T., Lipiec, A., Lisa, M. A., Liu, F., Liu, H., Liu, P., Liu, T., Liu, X., Liu, Y., Liu, Z., Ljubicic, T., Llope, W. J., Lomnitz, M., Longacre, R. S., Luo, S., Luo, X., Ma, G. L., Ma, L., Ma, R., Ma, Y. G., Magdy, N., Majka, R., Mallick, D., Margetis, S., Markert, C., Matis, H. S., Matonoha, O., Mazer, J. A., Meehan, K., Mei, J. C., Minaev, N. G., Mioduszewski, S., Mishra, D., Mohanty, B., Mondal, M. M., Mooney, I., Moravcova, Z., Morozov, D. A., Nasim, Md., Nayak, K., Nelson, J. M., Nemes, D. B., Nie, M., Nigmatkulov, G., Niida, T., Nogach, L. V., Nonaka, T., Odyniec, G., Ogawa, A., Oh, K., Oh, S., Okorokov, V. A., Page, B. S., Pak, R., Panebratsev, Y., Pawlik, B., Pawlowska, D., Pei, H., Perkins, C., Pintér, R. L., Pluta, J., Porter, J., Posik, M., Pruthi, N. K., Przybycien, M., Putschke, J., Quintero, A., Radhakrishnan, S. K., Ramachandran, S., Ray, R. L., Reed, R., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ruan, L., Rusnak, J., Rusnakova, O., Sahoo, N. R., Sahu, P. K., Salur, S., Sandweiss, J., Schambach, J., Schmidke, W. B., Schmitz, N., Schweid, B. R., Seck, F., Seger, J., Sergeeva, M., Seto, R., Seyboth, P., Shah, N., Shahaliev, E., Shanmuganathan, P. V., Shao, M., Shen, F., Shen, W. Q., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Siejka, S., Sikora, R., Simko, M., Singh, J., Singha, S., Smirnov, D., Smirnov, N., Solyst, W., Sorensen, P., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Stefaniak, M., Stewart, D. J., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Sugiura, T., Sumbera, M., Summa, B., Sun, X. M., Sun, Y., Surrow, B., Svirida, D. N., Szymanski, P., Tang, A. H., Tang, Z., Taranenko, A., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Tlusty, D., Todoroki, T., Tokarev, M., Tomkiel, C. A., Trentalange, S., Tribble, R. E., Tribedy, P., Tripathy, S. K., Tsai, O. D., Tu, B., Tu, Z., Ullrich, T., Underwood, D. G., Upsal, I., Van Buren, G., Vanek, J., Vasiliev, A. N., Vassiliev, I., Videbæk, F., Vokal, S., Voloshin, S. A., Wang, F., Wang, G., Wang, P., Wang, Y., Webb, J. C., Wen, L., Westfall, G. D., Wieman, H., Wissink, S. W., Witt, R., Wu, Y., Xiao, Z. G., Xie, G., Xie, W., Xu, H., Xu, N., Xu, Q. H., Xu, Y. F., Xu, Z., Yang, C., Yang, Q., Yang, S., Yang, Y., Yang, Z., Ye, Z., Yi, L., Yip, K., Yoo, I. -K., Zbroszczyk, H., Zha, W., Zhang, D., Zhang, L., Zhang, S., Zhang, X. P., Zhang, Y., Zhang, Z., Zhao, J., Zhong, C., Zhou, C., Zhu, X., Zhu, Z., Zurek, M., and Zyzak, M.

Subjects
Nuclear Experiment
Abstract

We present STAR measurements of strange hadron ($\mathrm{K}^{0}_{\mathrm S}$, $\Lambda$, $\overline{\Lambda}$, $\Xi^-$, $\overline{\Xi}^+$, $\Omega^-$, $\overline{\Omega}^+$, and $\phi$) production at mid-rapidity ($|y| < 0.5$) in Au+Au collisions at $\sqrt{s_{_{\mathrm{NN}}}}$ = 7.7 - 39 GeV from the Beam Energy Scan Program at the Relativistic Heavy Ion Collider (RHIC). Transverse momentum spectra, averaged transverse mass, and the overall integrated yields of these strange hadrons are presented versus the centrality and collision energy. Antibaryon-to-baryon ratios ($\overline{\Lambda}$/$\Lambda$, $\overline{\Xi}^+$/$\Xi^-$, $\overline{\Omega}^+$/$\Omega^-$) are presented as well, and used to test a thermal statistical model and to extract the temperature normalized strangeness and baryon chemical potentials at hadronic freeze-out ($\mu_{B}/T_{\rm ch}$ and $\mu_{S}/T_{\rm ch}$) in central collisions. Strange baryon-to-pion ratios are compared to various model predictions in central collisions for all energies. The nuclear modification factors ($R_{\textrm{CP}}$) and antibaryon-to-meson ratios as a function of transverse momentum are presented for all collision energies. The $\mathrm{K}^{0}_{\mathrm S}$ $R_{\textrm{CP}}$ shows no suppression for $p_{\rm T}$ up to 3.5 $\mathrm{GeV} / c$ at energies of 7.7 and 11.5 GeV. The $\overline{\Lambda}$/$\mathrm{K}^{0}_{\mathrm S}$ ratio also shows baryon-to-meson enhancement at intermediate $p_{\rm T}$ ($\approx$2.5 $\mathrm{GeV} / c$) in central collisions at energies above 19.6 GeV. Both observations suggest that there is likely a change of the underlying strange quark dynamics at collision energies below 19.6 GeV., Comment: 26 pages, 29 figures, version accepted by Physical Review C

Published
2019
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29. Longitudinal double-spin asymmetry for inclusive jet and dijet production in $pp$ collisions at $\sqrt{s} = 510$ GeV

Author

STAR Collaboration, Adam, J., Adamczyk, L., Adams, J. R., Adkins, J. K., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alekseev, I., Anderson, D. M., Aoyama, R., Aparin, A., Arkhipkin, D., Aschenauer, E. C., Ashraf, M. U., Atetalla, F., Attri, A., Averichev, G. S., Bairathi, V., Barish, K., Bassill, A. J., Behera, A., Bellwied, R., Bhasin, A., Bhati, A. K., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Brandenburg, J. D., Brandin, A. V., Bryslawskyj, J., Bunzarov, I., Butterworth, J., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Chakaberia, I., Chaloupka, P., Chan, B. K., Chang, F-H., Chang, Z., Chankova-Bunzarova, N., Chatterjee, A., Chattopadhyay, S., Chen, J. H., Chen, X., Cheng, J., Cherney, M., Christie, W., Crawford, H. J., Csanád, M., Das, S., Dedovich, T. G., Deppner, I. M., Derevschikov, A. A., Didenko, L., Dilks, C., Dong, X., Drachenberg, J. L., Dunlop, J. C., Edmonds, T., Elsey, N., Engelage, J., Eppley, G., Esha, R., Esumi, S., Evdokimov, O., Ewigleben, J., Eyser, O., Fatemi, R., Fazio, S., Federic, P., Fedorisin, J., Feng, Y., Filip, P., Finch, E., Fisyak, Y., Fulek, L., Gagliardi, C. A., Galatyuk, T., Geurts, F., Gibson, A., Gopal, K., Grosnick, D., Gupta, A., Guryn, W., Hamad, A. I., Hamed, A., Harris, J. W., He, L., Heppelmann, S., Herrmann, N., Holub, L., Hong, Y., Horvat, S., Huang, B., Huang, H. Z., Huang, S. L., Huang, T., Huang, X., Humanic, T. J., Huo, P., Igo, G., Jacobs, W. W., Jena, C., Jentsch, A., JI, Y., Jia, J., Jiang, K., Jowzaee, S., Ju, X., Judd, E. G., Kabana, S., Kagamaster, S., Kalinkin, D., Kang, K., Kapukchyan, D., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kelsey, M., Khyzhniak, Y. V., Kikoła, D. P., Kim, C., Kinghorn, T. A., Kisel, I., Kisiel, A., Kocan, M., Kochenda, L., Kosarzewski, L. K., Kramarik, L., Kravtsov, P., Krueger, K., Mudiyanselage, N. Kulathunga, Kumar, L., Elayavalli, R. Kunnawalkam, Kwasizur, J. H., Lacey, R., Landgraf, J. M., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Li, C., Li, W., Li, X., Li, Y., Liang, Y., Licenik, R., Lin, T., Lipiec, A., Lisa, M. A., Liu, F., Liu, H., Liu, P., Liu, T., Liu, X., Liu, Y., Liu, Z., Ljubicic, T., Llope, W. J., Lomnitz, M., Longacre, R. S., Luo, S., Luo, X., Ma, G. L., Ma, L., Ma, R., Ma, Y. G., Magdy, N., Majka, R., Mallick, D., Margetis, S., Markert, C., Matis, H. S., Matonoha, O., Mazer, J. A., Meehan, K., Mei, J. C., Minaev, N. G., Mioduszewski, S., Mishra, D., Mohanty, B., Mondal, M. M., Mooney, I., Moravcova, Z., Morozov, D. A., Nasim, Md., Nayak, K., Nelson, J. M., Nemes, D. B., Nie, M., Nigmatkulov, G., Niida, T., Nogach, L. V., Nonaka, T., Odyniec, G., Ogawa, A., Oh, K., Oh, S., Okorokov, V. A., Page, B. S., Pak, R., Panebratsev, Y., Pawlik, B., Pawlowska, D., Pei, H., Perkins, C., Pintér, R. L., Pluta, J., Porter, J., Posik, M., Pruthi, N. K., Przybycien, M., Putschke, J., Quintero, A., Radhakrishnan, S. K., Ramachandran, S., Ray, R. L., Reed, R., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ruan, L., Rusnak, J., Rusnakova, O., Sahoo, N. R., Sahu, P. K., Salur, S., Sandweiss, J., Schambach, J., Schmidke, W. B., Schmitz, N., Schweid, B. R., Seck, F., Seger, J., Sergeeva, M., Seto, R., Seyboth, P., Shah, N., Shahaliev, E., Shanmuganathan, P. V., Shao, M., Shen, F., Shen, W. Q., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Siejka, S., Sikora, R., Simko, M., Singh, J., Singha, S., Smirnov, D., Smirnov, N., Solyst, W., Sorensen, P., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Stefaniak, M., Stewart, D. J., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Sugiura, T., Sumbera, M., Summa, B., Sun, X. M., Sun, Y., Surrow, B., Svirida, D. N., Szymanski, P., Tang, A. H., Tang, Z., Taranenko, A., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Tlusty, D., Todoroki, T., Tokarev, M., Tomkiel, C. A., Trentalange, S., Tribble, R. E., Tribedy, P., Tripathy, S. K., Tsai, O. D., Tu, B., Tu, Z., Ullrich, T., Underwood, D. G., Upsal, I., Van Buren, G., Vanek, J., Vasiliev, A. N., Vassiliev, I., Videbæk, F., Vokal, S., Voloshin, S. A., Wang, F., Wang, G., Wang, P., Wang, Y., Webb, J. C., Wen, L., Westfall, G. D., Wieman, H., Wissink, S. W., Witt, R., Wu, Y., Xiao, Z. G., Xie, G., Xie, W., Xu, H., Xu, N., Xu, Q. H., Xu, Y. F., Xu, Z., Yang, C., Yang, Q., Yang, S., Yang, Y., Yang, Z., Ye, Z., Yi, L., Yip, K., Yoo, I. -K., Zbroszczyk, H., Zha, W., Zhang, D., Zhang, L., Zhang, S., Zhang, X. P., Zhang, Y., Zhang, Z., Zhao, J., Zhong, C., Zhou, C., Zhu, X., Zhu, Z., Zurek, M., and Zyzak, M.

Subjects
High Energy Physics - Experiment, Nuclear Experiment
Abstract

We report the first measurement of the inclusive jet and the dijet longitudinal double-spin asymmetries, $A_{LL}$, at midrapidity in polarized $pp$ collisions at a center-of-mass energy $\sqrt{s} = 510$ GeV. The inclusive jet $A_{LL}$ measurement is sensitive to the gluon helicity distribution down to a gluon momentum fraction of $x\approx 0.015$, while the dijet measurements, separated into four jet-pair topologies, provide constraints on the $x$ dependence of the gluon polarization. Both results are consistent with previous measurements made at $\sqrt{s}= 200$ GeV in the overlapping kinematic region, $x > 0.05$, and show good agreement with predictions from recent next-to-leading order global analyses.

Published
2019
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30. Measurement of inclusive $J/\psi$ suppression in Au+Au collisions at $\sqrt{s_{NN}}$ = 200 GeV through the dimuon channel at STAR

Author

STAR Collaboration, Adam, J., Adamczyk, L., Adams, J. R., Adkins, J. K., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alekseev, I., Anderson, D. M., Aoyama, R., Aparin, A., Arkhipkin, D., Aschenauer, E. C., Ashraf, M. U., Atetalla, F., Attri, A., Averichev, G. S., Bairathi, V., Barish, K., Bassill, A. J., Behera, A., Bellwied, R., Bhasin, A., Bhati, A. K., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Brandenburg, J. D., Brandin, A. V., Bryslawskyj, J., Bunzarov, I., Butterworth, J., Caines, H., Calderón~de~la~Barca~Sánchez, M., Cebra, D., Chakaberia, I., Chaloupka, P., Chan, B. K., Chang, F-H., Chang, Z., Chankova-Bunzarova, N., Chatterjee, A., Chattopadhyay, S., Chen, J. H., Chen, X., Cheng, J., Cherney, M., Christie, W., Crawford, H. J., Csanád, M., Das, S., Dedovich, T. G., Deppner, I. M., Derevschikov, A. A., Didenko, L., Dilks, C., Dong, X., Drachenberg, J. L., Dunlop, J. C., Edmonds, T., Elsey, N., Engelage, J., Eppley, G., Esha, R., Esumi, S., Evdokimov, O., Ewigleben, J., Eyser, O., Fatemi, R., Fazio, S., Federic, P., Fedorisin, J., Feng, Y., Filip, P., Finch, E., Fisyak, Y., Fulek, L., Gagliardi, C. A., Galatyuk, T., Geurts, F., Gibson, A., Gopal, K., Grosnick, D., Gupta, A., Guryn, W., Hamad, A. I., Hamed, A., Harris, J. W., He, L., Heppelmann, S., Herrmann, N., Holub, L., Hong, Y., Horvat, S., Huang, B., Huang, H. Z., Huang, S. L., Huang, T., Huang, X., Humanic, T. J., Huo, P., Igo, G., Jacobs, W. W., Jena, C., Jentsch, A., JI, Y., Jia, J., Jiang, K., Jowzaee, S., Ju, X., Judd, E. G., Kabana, S., Kagamaster, S., Kalinkin, D., Kang, K., Kapukchyan, D., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kelsey, M., Khyzhniak, Y. V., Kikoła, D. P., Kim, C., Kinghorn, T. A., Kisel, I., Kisiel, A., Kocan, M., Kochenda, L., Kosarzewski, L. K., Kramarik, L., Kravtsov, P., Krueger, K., Mudiyanselage, N. Kulathunga, Kumar, L., Elayavalli, R. Kunnawalkam, Kwasizur, J. H., Lacey, R., Landgraf, J. M., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Li, C., Li, W., Li, X., Li, Y., Liang, Y., Licenik, R., Lin, T., Lipiec, A., Lisa, M. A., Liu, F., Liu, H., Liu, P., Liu, T., Liu, X., Liu, Y., Liu, Z., Ljubicic, T., Llope, W. J., Lomnitz, M., Longacre, R. S., Luo, S., Luo, X., Ma, G. L., Ma, L., Ma, R., Ma, Y. G., Magdy, N., Majka, R., Mallick, D., Margetis, S., Markert, C., Matis, H. S., Matonoha, O., Mazer, J. A., Meehan, K., Mei, J. C., Minaev, N. G., Mioduszewski, S., Mishra, D., Mohanty, B., Mondal, M. M., Mooney, I., Moravcova, Z., Morozov, D. A., Nasim, Md., Nayak, K., Nelson, J. M., Nemes, D. B., Nie, M., Nigmatkulov, G., Niida, T., Nogach, L. V., Nonaka, T., Odyniec, G., Ogawa, A., Oh, K., Oh, S., Okorokov, V. A., Page, B. S., Pak, R., Panebratsev, Y., Pawlik, B., Pawlowska, D., Pei, H., Perkins, C., Pintér, R. L., Pluta, J., Porter, J., Posik, M., Pruthi, N. K., Przybycien, M., Putschke, J., Quintero, A., Radhakrishnan, S. K., Ramachandran, S., Ray, R. L., Reed, R., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ruan, L., Rusnak, J., Rusnakova, O., Sahoo, N. R., Sahu, P. K., Salur, S., Sandweiss, J., Schambach, J., Schmidke, W. B., Schmitz, N., Schweid, B. R., Seck, F., Seger, J., Sergeeva, M., Seto, R., Seyboth, P., Shah, N., Shahaliev, E., Shanmuganathan, P. V., Shao, M., Shen, F., Shen, W. Q., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Siejka, S., Sikora, R., Simko, M., Singh, J., Singha, S., Smirnov, D., Smirnov, N., Solyst, W., Sorensen, P., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Stefaniak, M., Stewart, D. J., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Sugiura, T., Sumbera, M., Summa, B., Sun, X. M., Sun, Y., Surrow, B., Svirida, D. N., Szymanski, P., Tang, A. H., Tang, Z., Taranenko, A., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Tlusty, D., Todoroki, T., Tokarev, M., Tomkiel, C. A., Trentalange, S., Tribble, R. E., Tribedy, P., Tripathy, S. K., Tsai, O. D., Tu, B., Tu, Z., Ullrich, T., Underwood, D. G., Upsal, I., Van Buren, G., Vanek, J., Vasiliev, A. N., Vassiliev, I., Videbæk, F., Vokal, S., Voloshin, S. A., Wang, F., Wang, G., Wang, P., Wang, Y., Webb, J. C., Wen, L., Westfall, G. D., Wieman, H., Wissink, S. W., Witt, R., Wu, Y., Xiao, Z. G., Xie, G., Xie, W., Xu, H., Xu, N., Xu, Q. H., Xu, Y. F., Xu, Z., Yang, C., Yang, Q., Yang, S., Yang, Y., Yang, Z., Ye, Z., Yi, L., Yip, K., Yoo, I. -K., Zbroszczyk, H., Zha, W., Zhang, D., Zhang, L., Zhang, S., Zhang, X. P., Zhang, Y., Zhang, Z., Zhao, J., Zhong, C., Zhou, C., Zhu, X., Zhu, Z., Zurek, M., and Zyzak, M.

Subjects
Nuclear Experiment
Abstract

$J/\psi$ suppression has long been considered a sensitive signature of the formation of the Quark-Gluon Plasma (QGP) in relativistic heavy-ion collisions. In this letter, we present the first measurement of inclusive $J/\psi$ production at mid-rapidity through the dimuon decay channel in Au+Au collisions at $\sqrt{s_{NN}}$ = 200 GeV with the STAR experiment. These measurements became possible after the installation of the Muon Telescope Detector was completed in 2014. The $J/\psi$ yields are measured in a wide transverse momentum ($p_{\rm{T}}$) range of 0.15 GeV/$c$ to 12 GeV/$c$ from central to peripheral collisions. They extend the kinematic reach of previous measurements at RHIC with improved precision. In the 0-10% most central collisions, the $J/\psi$ yield is suppressed by a factor of approximately 3 for $p_{\rm{T}}>5$ GeV/$c$ relative to that in p+p collisions scaled by the number of binary nucleon-nucleon collisions. The $J/\psi$ nuclear modification factor displays little dependence on $p_{\rm{T}}$ in all centrality bins. Model calculations can qualitatively describe the data, providing further evidence for the color-screening effect experienced by $J/\psi$ mesons in the QGP.

Published
2019
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31. Polarization of $\Lambda$ ($\bar{\Lambda}$) hyperons along the beam direction in Au+Au collisions at $\sqrt{s_{_{NN}}}$ = 200 GeV

Author

STAR Collaboration, Adam, J., Adamczyk, L., Adams, J. R., Adkins, J. K., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alekseev, I., Anderson, D. M., Aoyama, R., Aparin, A., Arkhipkin, D., Aschenauer, E. C., Ashraf, M. U., Atetalla, F., Attri, A., Averichev, G. S., Bairathi, V., Barish, K., Bassill, A. J., Behera, A., Bellwied, R., Bhasin, A., Bhati, A. K., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Brandenburg, J. D., Brandin, A. V., Bryslawskyj, J., Bunzarov, I., Butterworth, J., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Chakaberia, I., Chaloupka, P., Chan, B. K., Chang, F-H., Chang, Z., Chankova-Bunzarova, N., Chatterjee, A., Chattopadhyay, S., Chen, J. H., Chen, X., Cheng, J., Cherney, M., Christie, W., Crawford, H. J., Csanád, M., Das, S., Dedovich, T. G., Deppner, I. M., Derevschikov, A. A., Didenko, L., Dilks, C., Dong, X., Drachenberg, J. L., Dunlop, J. C., Edmonds, T., Elsey, N., Engelage, J., Eppley, G., Esha, R., Esumi, S., Evdokimov, O., Ewigleben, J., Eyser, O., Fatemi, R., Fazio, S., Federic, P., Fedorisin, J., Feng, Y., Filip, P., Finch, E., Fisyak, Y., Fulek, L., Gagliardi, C. A., Galatyuk, T., Geurts, F., Gibson, A., Gopal, K., Grosnick, D., Gupta, A., Guryn, W., Hamad, A. I., Hamed, A., Harris, J. W., He, L., Heppelmann, S., Herrmann, N., Holub, L., Hong, Y., Horvat, S., Huang, B., Huang, H. Z., Huang, S. L., Huang, T., Huang, X., Humanic, T. J., Huo, P., Igo, G., Jacobs, W. W., Jena, C., Jentsch, A., JI, Y., Jia, J., Jiang, K., Jowzaee, S., Ju, X., Judd, E. G., Kabana, S., Kagamaster, S., Kalinkin, D., Kang, K., Kapukchyan, D., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kelsey, M., Khyzhniak, Y. V., Kikoła, D. P., Kim, C., Kinghorn, T. A., Kisel, I., Kisiel, A., Kocan, M., Kochenda, L., Kosarzewski, L. K., Kramarik, L., Kravtsov, P., Krueger, K., Mudiyanselage, N. Kulathunga, Kumar, L., Elayavalli, R. Kunnawalkam, Kwasizur, J. H., Lacey, R., Landgraf, J. M., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Li, C., Li, W., Li, X., Li, Y., Liang, Y., Licenik, R., Lin, T., Lipiec, A., Lisa, M. A., Liu, F., Liu, H., Liu, P., Liu, T., Liu, X., Liu, Y., Liu, Z., Ljubicic, T., Llope, W. J., Lomnitz, M., Longacre, R. S., Luo, S., Luo, X., Ma, G. L., Ma, L., Ma, R., Ma, Y. G., Magdy, N., Majka, R., Mallick, D., Margetis, S., Markert, C., Matis, H. S., Matonoha, O., Mazer, J. A., Meehan, K., Mei, J. C., Minaev, N. G., Mioduszewski, S., Mishra, D., Mohanty, B., Mondal, M. M., Mooney, I., Moravcova, Z., Morozov, D. A., Nasim, Md., Nayak, K., Nelson, J. M., Nemes, D. B., Nie, M., Nigmatkulov, G., Niida, T., Nogach, L. V., Nonaka, T., Odyniec, G., Ogawa, A., Oh, K., Oh, S., Okorokov, V. A., Page, B. S., Pak, R., Panebratsev, Y., Pawlik, B., Pawlowska, D., Pei, H., Perkins, C., Pintér, R. L., Pluta, J., Porter, J., Posik, M., Pruthi, N. K., Przybycien, M., Putschke, J., Quintero, A., Radhakrishnan, S. K., Ramachandran, S., Ray, R. L., Reed, R., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ruan, L., Rusnak, J., Rusnakova, O., Sahoo, N. R., Sahu, P. K., Salur, S., Sandweiss, J., Schambach, J., Schmidke, W. B., Schmitz, N., Schweid, B. R., Seck, F., Seger, J., Sergeeva, M., Seto, R., Seyboth, P., Shah, N., Shahaliev, E., Shanmuganathan, P. V., Shao, M., Shen, F., Shen, W. Q., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Siejka, S., Sikora, R., Simko, M., Singh, J., Singha, S., Smirnov, D., Smirnov, N., Solyst, W., Sorensen, P., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Stefaniak, M., Stewart, D. J., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Sugiura, T., Sumbera, M., Summa, B., Sun, X. M., Sun, Y., Surrow, B., Svirida, D. N., Szymanski, P., Tang, A. H., Tang, Z., Taranenko, A., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Tlusty, D., Todoroki, T., Tokarev, M., Tomkiel, C. A., Trentalange, S., Tribble, R. E., Tribedy, P., Tripathy, S. K., Tsai, O. D., Tu, B., Tu, Z., Ullrich, T., Underwood, D. G., Upsal, I., Van Buren, G., Vanek, J., Vasiliev, A. N., Vassiliev, I., Videbæk, F., Vokal, S., Voloshin, S. A., Wang, F., Wang, G., Wang, P., Wang, Y., Webb, J. C., Wen, L., Westfall, G. D., Wieman, H., Wissink, S. W., Witt, R., Wu, Y., Xiao, Z. G., Xie, G., Xie, W., Xu, H., Xu, N., Xu, Q. H., Xu, Y. F., Xu, Z., Yang, C., Yang, Q., Yang, S., Yang, Y., Yang, Z., Ye, Z., Yi, L., Yip, K., Yoo, I. -K., Zbroszczyk, H., Zha, W., Zhang, D., Zhang, L., Zhang, S., Zhang, X. P., Zhang, Y., Zhang, Z., Zhao, J., Zhong, C., Zhou, C., Zhu, X., Zhu, Z., Zurek, M., and Zyzak, M.

Subjects
Nuclear Experiment
Abstract

The $\Lambda$ ($\bar{\Lambda}$) hyperon polarization along the beam direction has been measured for the first time in Au+Au collisions at $\sqrt{s_{_{NN}}}$ = 200 GeV. The polarization dependence on the hyperons' emission angle relative to the second-order event plane exhibits a sine modulation, indicating a quadrupole pattern of the vorticity component along the beam direction. The polarization is found to increase in more peripheral collisions, and shows no strong transverse momentum ($p_T$) dependence at $p_T>1$ GeV/$c$. The magnitude of the signal is about five times smaller than those predicted by hydrodynamic and multiphase transport models; the observed phase of the emission angle dependence is also opposite to these model predictions. In contrast, blast-wave model calculations reproduce the modulation phase measured in the data and capture the centrality and transverse momentum dependence of the signal once the model is required to reproduce the azimuthal dependence of the Gaussian source radii measured via the Hanbury-Brown and Twiss intensity interferometry technique., Comment: 8 pages, 4 figures, Submitted to Phys. Rev. Lett

Published
2019
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32. Measurements of the transverse-momentum-dependent cross sections of $J/\psi$ production at mid-rapidity in proton+proton collisions at $\sqrt{s} =$ 510 and 500 GeV with the STAR detector

Author

STAR Collaboration, Adam, J., Adamczyk, L., Adams, J. R., Adkins, J. K., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alekseev, I., Anderson, D. M., Aoyama, R., Aparin, A., Arkhipkin, D., Aschenauer, E. C., Ashraf, M. U., Atetalla, F., Attri, A., Averichev, G. S., Bairathi, V., Barish, K., Bassill, A. J., Behera, A., Bellwied, R., Bhasin, A., Bhati, A. K., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Brandenburg, J. D., Brandin, A. V., Bryslawskyj, J., Bunzarov, I., Butterworth, J., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Chakaberia, I., Chaloupka, P., Chan, B. K., Chang, F-H., Chang, Z., Chankova-Bunzarova, N., Chatterjee, A., Chattopadhyay, S., Chen, J. H., Chen, X., Cheng, J., Cherney, M., Christie, W., Crawford, H. J., Csanád, M., Das, S., Dedovich, T. G., Deppner, I. M., Derevschikov, A. A., Didenko, L., Dilks, C., Dong, X., Drachenberg, J. L., Dunlop, J. C., Edmonds, T., Elsey, N., Engelage, J., Eppley, G., Esha, R., Esumi, S., Evdokimov, O., Ewigleben, J., Eyser, O., Fatemi, R., Fazio, S., Federic, P., Fedorisin, J., Feng, Y., Filip, P., Finch, E., Fisyak, Y., Fulek, L., Gagliardi, C. A., Galatyuk, T., Geurts, F., Gibson, A., Gopal, K., Grosnick, D., Gupta, A., Guryn, W., Hamad, A. I., Hamed, A., Harris, J. W., He, L., Heppelmann, S., Herrmann, N., Holub, L., Hong, Y., Horvat, S., Huang, B., Huang, H. Z., Huang, S. L., Huang, T., Huang, X., Humanic, T. J., Huo, P., Igo, G., Jacobs, W. W., Jena, C., Jentsch, A., JI, Y., Jia, J., Jiang, K., Jowzaee, S., Ju, X., Judd, E. G., Kabana, S., Kagamaster, S., Kalinkin, D., Kang, K., Kapukchyan, D., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kelsey, M., Khyzhniak, Y. V., Kikoła, D. P., Kim, C., Kinghorn, T. A., Kisel, I., Kisiel, A., Kocan, M., Kochenda, L., Kosarzewski, L. K., Kramarik, L., Kravtsov, P., Krueger, K., Mudiyanselage, N. Kulathunga, Kumar, L., Elayavalli, R. Kunnawalkam, Kwasizur, J. H., Lacey, R., Landgraf, J. M., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Li, C., Li, W., Li, X., Li, Y., Liang, Y., Licenik, R., Lin, T., Lipiec, A., Lisa, M. A., Liu, F., Liu, H., Liu, P., Liu, T., Liu, X., Liu, Y., Liu, Z., Ljubicic, T., Llope, W. J., Lomnitz, M., Longacre, R. S., Luo, S., Luo, X., Ma, G. L., Ma, L., Ma, R., Ma, Y. G., Magdy, N., Majka, R., Mallick, D., Margetis, S., Markert, C., Matis, H. S., Matonoha, O., Mazer, J. A., Meehan, K., Mei, J. C., Minaev, N. G., Mioduszewski, S., Mishra, D., Mohanty, B., Mondal, M. M., Mooney, I., Moravcova, Z., Morozov, D. A., Nasim, Md., Nayak, K., Nelson, J. M., Nemes, D. B., Nie, M., Nigmatkulov, G., Niida, T., Nogach, L. V., Nonaka, T., Odyniec, G., Ogawa, A., Oh, K., Oh, S., Okorokov, V. A., Page, B. S., Pak, R., Panebratsev, Y., Pawlik, B., Pawlowska, D., Pei, H., Perkins, C., Pintér, R. L., Pluta, J., Porter, J., Posik, M., Pruthi, N. K., Przybycien, M., Putschke, J., Quintero, A., Radhakrishnan, S. K., Ramachandran, S., Ray, R. L., Reed, R., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ruan, L., Rusnak, J., Rusnakova, O., Sahoo, N. R., Sahu, P. K., Salur, S., Sandweiss, J., Schambach, J., Schmidke, W. B., Schmitz, N., Schweid, B. R., Seck, F., Seger, J., Sergeeva, M., Seto, R., Seyboth, P., Shah, N., Shahaliev, E., Shanmuganathan, P. V., Shao, M., Shen, F., Shen, W. Q., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Siejka, S., Sikora, R., Simko, M., Singh, J., Singha, S., Smirnov, D., Smirnov, N., Solyst, W., Sorensen, P., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Stefaniak, M., Stewart, D. J., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Sugiura, T., Sumbera, M., Summa, B., Sun, X. M., Sun, Y., Surrow, B., Svirida, D. N., Szymanski, P., Tang, A. H., Tang, Z., Taranenko, A., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Tlusty, D., Todoroki, T., Tokarev, M., Tomkiel, C. A., Trentalange, S., Tribble, R. E., Tribedy, P., Tripathy, S. K., Tsai, O. D., Tu, B., Tu, Z., Ullrich, T., Underwood, D. G., Upsal, I., Van Buren, G., Vanek, J., Vasiliev, A. N., Vassiliev, I., Videbæk, F., Vokal, S., Voloshin, S. A., Wang, F., Wang, G., Wang, P., Wang, Y., Webb, J. C., Wen, L., Westfall, G. D., Wieman, H., Wissink, S. W., Witt, R., Wu, Y., Xiao, Z. G., Xie, G., Xie, W., Xu, H., Xu, N., Xu, Q. H., Xu, Y. F., Xu, Z., Yang, C., Yang, Q., Yang, S., Yang, Y., Yang, Z., Ye, Z., Yi, L., Yip, K., Yoo, I. -K., Zbroszczyk, H., Zha, W., Zhang, D., Zhang, L., Zhang, S., Zhang, X. P., Zhang, Y., Zhang, Z., Zhao, J., Zhong, C., Zhou, C., Zhu, X., Zhu, Z., Zurek, M., and Zyzak, M.

Subjects
High Energy Physics - Experiment, Nuclear Experiment
Abstract

We present measurements of the differential cross sections of inclusive $J/\psi$ meson production as a function of transverse momentum ($p_{T}^{J/\psi}$) using the $\mu^{+}\mu^{-}$ and $e^{+}e^{-}$ decay channels in proton+proton collisions at center-of-mass energies of 510 and 500 GeV, respectively, recorded by the STAR detector at the Relativistic Heavy Ion Collider. The measurement from the $\mu^{+}\mu^{-}$ channel is for 0 $< p_{T}^{J/\psi} <$ 9 GeV/$c$ and rapidity range $|y^{J/\psi}| < $ 0.4, and that from the $e^{+}e^{-}$ channel is for 4 $< p_{T}^{J/\psi} <$ 20 GeV/$c$ and $|y^{J/\psi}| < $ 1.0. The $\psi(2S)$ to $J/\psi$ ratio is also measured for 4 $< p_{T}^{\rm meson} <$ 12 GeV/$c$ through the $e^{+}e^{-}$ decay channel. Model calculations, which incorporate different approaches toward the $J/\psi$ production mechanism, are compared with experimental results and show reasonable agreement within uncertainties.

Published
2019
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33. First observation of the directed flow of $D^{0}$ and $\overline{D^0}$ in Au+Au collisions at $\sqrt{s_{\rm NN}}$ = 200~GeV

Author

STAR Collaboration, Adam, J., Adamczyk, L., Adams, J. R., Adkins, J. K., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alekseev, I., Anderson, D. M., Aoyama, R., Aparin, A., Arkhipkin, D., Aschenauer, E. C., Ashraf, M. U., Atetalla, F., Attri, A., Averichev, G. S., Bairathi, V., Barish, K., Bassill, A. J., Behera, A., Bellwied, R., Bhasin, A., Bhati, A. K., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Brandenburg, J. D., Brandin, A. V., Bryslawskyj, J., Bunzarov, I., Butterworth, J., Caines, H., Calderón~de~la~Barca~Sánchez, M., Cebra, D., Chakaberia, I., Chaloupka, P., Chan, B. K., Chang, F-H., Chang, Z., Chankova-Bunzarova, N., Chatterjee, A., Chattopadhyay, S., Chen, J. H., Chen, X., Cheng, J., Cherney, M., Christie, W., Crawford, H. J., Csanád, M., Das, S., Dedovich, T. G., Deppner, I. M., Derevschikov, A. A., Didenko, L., Dilks, C., Dong, X., Drachenberg, J. L., Dunlop, J. C., Edmonds, T., Elsey, N., Engelage, J., Eppley, G., Esha, R., Esumi, S., Evdokimov, O., Ewigleben, J., Eyser, O., Fatemi, R., Fazio, S., Federic, P., Fedorisin, J., Feng, Y., Filip, P., Finch, E., Fisyak, Y., Fulek, L., Gagliardi, C. A., Galatyuk, T., Geurts, F., Gibson, A., Gopal, K., Grosnick, D., Gupta, A., Guryn, W., Hamad, A. I., Hamed, A., Harris, J. W., He, L., Heppelmann, S., Herrmann, N., Holub, L., Hong, Y., Horvat, S., Huang, B., Huang, H. Z., Huang, S. L., Huang, T., Huang, X., Humanic, T. J., Huo, P., Igo, G., Jacobs, W. W., Jena, C., Jentsch, A., JI, Y., Jia, J., Jiang, K., Jowzaee, S., Ju, X., Judd, E. G., Kabana, S., Kagamaster, S., Kalinkin, D., Kang, K., Kapukchyan, D., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kelsey, M., Khyzhniak, Y. V., Kikoła, D. P., Kim, C., Kinghorn, T. A., Kisel, I., Kisiel, A., Kocan, M., Kochenda, L., Kosarzewski, L. K., Kramarik, L., Kravtsov, P., Krueger, K., Mudiyanselage, N. Kulathunga, Kumar, L., Elayavalli, R. Kunnawalkam, Kwasizur, J. H., Lacey, R., Landgraf, J. M., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Li, C., Li, W., Li, X., Li, Y., Liang, Y., Licenik, R., Lin, T., Lipiec, A., Lisa, M. A., Liu, F., Liu, H., Liu, P., Liu, T., Liu, X., Liu, Y., Liu, Z., Ljubicic, T., Llope, W. J., Lomnitz, M., Longacre, R. S., Luo, S., Luo, X., Ma, G. L., Ma, L., Ma, R., Ma, Y. G., Magdy, N., Majka, R., Mallick, D., Margetis, S., Markert, C., Matis, H. S., Matonoha, O., Mazer, J. A., Meehan, K., Mei, J. C., Minaev, N. G., Mioduszewski, S., Mishra, D., Mohanty, B., Mondal, M. M., Mooney, I., Moravcova, Z., Morozov, D. A., Nasim, Md., Nayak, K., Nelson, J. M., Nemes, D. B., Nie, M., Nigmatkulov, G., Niida, T., Nogach, L. V., Nonaka, T., Odyniec, G., Ogawa, A., Oh, K., Oh, S., Okorokov, V. A., Page, B. S., Pak, R., Panebratsev, Y., Pawlik, B., Pawlowska, D., Pei, H., Perkins, C., Pintér, R. L., Pluta, J., Porter, J., Posik, M., Pruthi, N. K., Przybycien, M., Putschke, J., Quintero, A., Radhakrishnan, S. K., Ramachandran, S., Ray, R. L., Reed, R., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ruan, L., Rusnak, J., Rusnakova, O., Sahoo, N. R., Sahu, P. K., Salur, S., Sandweiss, J., Schambach, J., Schmidke, W. B., Schmitz, N., Schweid, B. R., Seck, F., Seger, J., Sergeeva, M., Seto, R., Seyboth, P., Shah, N., Shahaliev, E., Shanmuganathan, P. V., Shao, M., Shen, F., Shen, W. Q., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Siejka, S., Sikora, R., Simko, M., Singh, J., Singha, S., Smirnov, D., Smirnov, N., Solyst, W., Sorensen, P., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Stefaniak, M., Stewart, D. J., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Sugiura, T., Sumbera, M., Summa, B., Sun, X. M., Sun, Y., Surrow, B., Svirida, D. N., Szymanski, P., Tang, A. H., Tang, Z., Taranenko, A., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Tlusty, D., Todoroki, T., Tokarev, M., Tomkiel, C. A., Trentalange, S., Tribble, R. E., Tribedy, P., Tripathy, S. K., Tsai, O. D., Tu, B., Ullrich, T., Underwood, D. G., Upsal, I., Van Buren, G., Vanek, J., Vasiliev, A. N., Vassiliev, I., Videbæk, F., Vokal, S., Voloshin, S. A., Wang, F., Wang, G., Wang, P., Wang, Y., Webb, J. C., Wen, L., Westfall, G. D., Wieman, H., Wissink, S. W., Witt, R., Wu, Y., Xiao, Z. G., Xie, G., Xie, W., Xu, H., Xu, N., Xu, Q. H., Xu, Y. F., Xu, Z., Yang, C., Yang, Q., Yang, S., Yang, Y., Yang, Z., Ye, Z., Yi, L., Yip, K., Yoo, I. -K., Zbroszczyk, H., Zha, W., Zhang, D., Zhang, L., Zhang, S., Zhang, X. P., Zhang, Y., Zhang, Z., Zhao, J., Zhong, C., Zhou, C., Zhu, X., Zhu, Z., Zurek, M., and Zyzak, M.

Subjects
Nuclear Experiment, High Energy Physics - Experiment, Nuclear Theory
Abstract

We report the first measurement of rapidity-odd directed flow ($v_{1}$) for $D^{0}$ and $\overline{D^{0}}$ mesons at mid-rapidity ($|y| < 0.8$) in Au+Au collisions at $\sqrt{s_{\rm NN}}$ = 200\,GeV using the STAR detector at the Relativistic Heavy Ion Collider. In 10--80\% Au+Au collisions, the slope of the $v_{1}$ rapidity dependence ($dv_{1}/dy$), averaged over $D^{0}$ and $\overline{D^{0}}$ mesons, is -0.080 $\pm$ 0.017 (stat.) $\pm$ 0.016 (syst.) for transverse momentum $p_{\rm T}$ above 1.5~GeV/$c$. The absolute value of $D^0$-meson $dv_1/dy$ is about 25 times larger than that for charged kaons, with 3.4$\sigma$ significance. These data give a unique insight into the initial tilt of the produced matter, and offer constraints on the geometric and transport parameters of the hot QCD medium created in relativistic heavy-ion collisions., Comment: Submitted to Phys. Rev. Lett

Published
2019
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34. Measurement of the mass difference and the binding energy of the hypertriton and antihypertriton

Author

STAR Collaboration, Adam, J., Adamczyk, L., Adams, J. R., Adkins, J. K., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alekseev, I., Anderson, D. M., Aoyama, R., Aparin, A., Arkhipkin, D., Aschenauer, E. C., Ashraf, M. U., Atetalla, F., Attri, A., Averichev, G. S., Bairathi, V., Barish, K., Bassill, A. J., Behera, A., Bellwied, R., Bhasin, A., Bhati, A. K., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Brandenburg, J. D., Brandin, A. V., Bryslawskyj, J., Bunzarov, I., Butterworth, J., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Chakaberia, I., Chaloupka, P., Chan, B. K., Chang, F-H., Chang, Z., Chankova-Bunzarova, N., Chatterjee, A., Chattopadhyay, S., Chen, J. H., Chen, X., Cheng, J., Cherney, M., Christie, W., Crawford, H. J., Csanád, M., Das, S., Dedovich, T. G., Deppner, I. M., Derevschikov, A. A., Didenko, L., Dilks, C., Dong, X., Drachenberg, J. L., Dunlop, J. C., Edmonds, T., Elsey, N., Engelage, J., Eppley, G., Esha, R., Esumi, S., Evdokimov, O., Ewigleben, J., Eyser, O., Fatemi, R., Fazio, S., Federic, P., Fedorisin, J., Feng, Y., Filip, P., Finch, E., Fisyak, Y., Fulek, L., Gagliardi, C. A., Galatyuk, T., Geurts, F., Gibson, A., Grosnick, D., Gupta, A., Guryn, W., Hamad, A. I., Hamed, A., Harris, J. W., He, L., Heppelmann, S., Herrmann, N., Holub, L., Hong, Y., Horvat, S., Huang, B., Huang, H. Z., Huang, S. L., Huang, T., Huang, X., Humanic, T. J., Huo, P., Igo, G., Jacobs, W. W., Jentsch, A., JI, Y., Jia, J., Jiang, K., Jowzaee, S., Ju, X., Judd, E. G., Kabana, S., Kagamaster, S., Kalinkin, D., Kang, K., Kapukchyan, D., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kelsey, M., Khyzhniak, Y. V., Kikoła, D. P., Kim, C., Kinghorn, T. A., Kisel, I., Kisiel, A., Kocan, M., Kochenda, L., Kosarzewski, L. K., Kramarik, L., Kravtsov, P., Krueger, K., Mudiyanselage, N. Kulathunga, Kumar, L., Elayavalli, R. Kunnawalkam, Kwasizur, J. H., Lacey, R., Landgraf, J. M., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Li, C., Li, W., Li, X., Li, Y., Liang, Y., Licenik, R., Lin, T., Lipiec, A., Lisa, M. A., Liu, F., Liu, H., Liu, P., Liu, T., Liu, X., Liu, Y., Liu, Z., Ljubicic, T., Llope, W. J., Lomnitz, M., Longacre, R. S., Luo, S., Luo, X., Ma, G. L., Ma, L., Ma, R., Ma, Y. G., Magdy, N., Majka, R., Mallick, D., Margetis, S., Markert, C., Matis, H. S., Matonoha, O., Mazer, J. A., Meehan, K., Mei, J. C., Minaev, N. G., Mioduszewski, S., Mishra, D., Mohanty, B., Mondal, M. M., Mooney, I., Moravcova, Z., Morozov, D. A., Nasim, Md., Nayak, K., Nelson, J. M., Nemes, D. B., Nie, M., Nigmatkulov, G., Niida, T., Nogach, L. V., Nonaka, T., Odyniec, G., Ogawa, A., Oh, K., Oh, S., Okorokov, V. A., Page, B. S., Pak, R., Panebratsev, Y., Pawlik, B., Pawlowska, D., Pei, H., Perkins, C., Pintér, R. L., Pluta, J., Porter, J., Posik, M., Pruthi, N. K., Przybycien, M., Putschke, J., Quintero, A., Radhakrishnan, S. K., Ramachandran, S., Ray, R. L., Reed, R., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ruan, L., Rusnak, J., Rusnakova, O., Sahoo, N. R., Sahu, P. K., Salur, S., Sandweiss, J., Schambach, J., Schmidke, W. B., Schmitz, N., Schweid, B. R., Seck, F., Seger, J., Sergeeva, M., Seto, R., Seyboth, P., Shah, N., Shahaliev, E., Shanmuganathan, P. V., Shao, M., Shen, F., Shen, W. Q., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Siejka, S., Sikora, R., Simko, M., Singh, J., Singha, S., Smirnov, D., Smirnov, N., Solyst, W., Sorensen, P., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Stefaniak, M., Stewart, D. J., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Sugiura, T., Sumbera, M., Summa, B., Sun, X. M., Sun, Y., Surrow, B., Svirida, D. N., Szymanski, P., Tang, A. H., Tang, Z., Taranenko, A., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Tlusty, D., Todoroki, T., Tokarev, M., Tomkiel, C. A., Trentalange, S., Tribble, R. E., Tribedy, P., Tripathy, S. K., Tsai, O. D., Tu, B., Ullrich, T., Underwood, D. G., Upsal, I., Van Buren, G., Vanek, J., Vasiliev, A. N., Vassiliev, I., Videbæk, F., Vokal, S., Voloshin, S. A., Wang, F., Wang, G., Wang, P., Wang, Y., Webb, J. C., Wen, L., Westfall, G. D., Wieman, H., Wissink, S. W., Witt, R., Wu, Y., Xiao, Z. G., Xie, G., Xie, W., Xu, H., Xu, N., Xu, Q. H., Xu, Y. F., Xu, Z., Yang, C., Yang, Q., Yang, S., Yang, Y., Yang, Z., Ye, Z., Yi, L., Yip, K., Yoo, I. -K., Zbroszczyk, H., Zha, W., Zhang, D., Zhang, L., Zhang, S., Zhang, X. P., Zhang, Y., Zhang, Z., Zhao, J., Zhong, C., Zhou, C., Zhu, X., Zhu, Z., Zurek, M., and Zyzak, M.

Subjects
High Energy Physics - Experiment, Nuclear Experiment, Nuclear Theory
Abstract

According to the CPT theorem, which states that the combined operation of charge conjugation, parity transformation and time reversal must be conserved, particles and their antiparticles should have the same mass and lifetime but opposite charge and magnetic moment. Here, we test CPT symmetry in a nucleus containing a strange quark, more specifically in the hypertriton. This hypernucleus is the lightest one yet discovered and consists of a proton, a neutron, and a $\Lambda$ hyperon. With data recorded by the STAR detector{\cite{TPC,HFT,TOF}} at the Relativistic Heavy Ion Collider, we measure the $\Lambda$ hyperon binding energy $B_{\Lambda}$ for the hypertriton, and find that it differs from the widely used value{\cite{B_1973}} and from predictions{\cite{2019_weak, 1995_weak, 2002_weak, 2014_weak}}, where the hypertriton is treated as a weakly bound system. Our results place stringent constraints on the hyperon-nucleon interaction{\cite{Hammer2002, STAR-antiH3L}}, and have implications for understanding neutron star interiors, where strange matter may be present{\cite{Chatterjee2016}}. A precise comparison of the masses of the hypertriton and the antihypertriton allows us to test CPT symmetry in a nucleus with strangeness for the first time, and we observe no deviation from the expected exact symmetry.

Published
2019
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35. Beam energy dependence of (anti-)deuteron production in Au+Au collisions at RHIC

Author

Adam, J., Adamczyk, L., Adams, J. R., Adkins, J. K., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alekseev, I., Anderson, D. M., Aoyama, R., Aparin, A., Arkhipkin, D., Aschenauer, E. C., Ashraf, M. U., Atetalla, F., Attri, A., Averichev, G. S., Bairathi, V., Barish, K., Bassill, A. J., Behera, A., Bellwied, R., Bhasin, A., Bhati, A. K., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Brandenburg, J. D., Brandin, A. V., Bryslawskyj, J., Bunzarov, I., Butterworth, J., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Chakaberia, I., Chaloupka, P., Chan, B. K., Chang, F-H., Chang, Z., Chankova-Bunzarova, N., Chatterjee, A., Chattopadhyay, S., Chen, J. H., Chen, X., Cheng, J., Cherney, M., Christie, W., Crawford, H. J., Csanád, M., Das, S., Dedovich, T. G., Deppner, I. M., Derevschikov, A. A., Didenko, L., Dilks, C., Dong, X., Drachenberg, J. L., Dunlop, J. C., Edmonds, T., Elsey, N., Engelage, J., Eppley, G., Esha, R., Esumi, S., Evdokimov, O., Ewigleben, J., Eyser, O., Fatemi, R., Fazio, S., Federic, P., Fedorisin, J., Feng, Y., Filip, P., Finch, E., Fisyak, Y., Fulek, L., Gagliardi, C. A., Galatyuk, T., Geurts, F., Gibson, A., Grosnick, D., Gupta, A., Guryn, W., Hamad, A. I., Hamed, A., Harris, J. W., He, L., Heppelmann, S., Herrmann, N., Holub, L., Hong, Y., Horvat, S., Huang, B., Huang, H. Z., Huang, S. L., Huang, T., Huang, X., Humanic, T. J., Huo, P., Igo, G., Jacobs, W. W., Jentsch, A., Jia, J., Jiang, K., Jowzaee, S., Ju, X., Judd, E. G., Kabana, S., Kagamaster, S., Kalinkin, D., Kang, K., Kapukchyan, D., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kelsey, M., Khyzhniak, Y. V., Kikoła, D. P., Kim, C., Kinghorn, T. A., Kisel, I., Kisiel, A., Kocan, M., Kochenda, L., Kosarzewski, L. K., Kramarik, L., Kravtsov, P., Krueger, K., Mudiyanselage, N. Kulathunga, Kumar, L., Elayavalli, R. Kunnawalkam, Kwasizur, J. H., Lacey, R., Landgraf, J. M., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Li, C., Li, W., Li, X., Li, Y., Liang, Y., Licenik, R., Lin, T., Lipiec, A., Lisa, M. A., Liu, F., Liu, H., Liu, P., Liu, T., Liu, X., Liu, Y., Liu, Z., Ljubicic, T., Llope, W. J., Lomnitz, M., Longacre, R. S., Luo, S., Luo, X., Ma, G. L., Ma, L., Ma, R., Ma, Y. G., Magdy, N., Majka, R., Mallick, D., Margetis, S., Markert, C., Matis, H. S., Matonoha, O., Mazer, J. A., Meehan, K., Mei, J. C., Minaev, N. G., Mioduszewski, S., Mishra, D., Mohanty, B., Mondal, M. M., Mooney, I., Moravcova, Z., Morozov, D. A., Nasim, Md., Nayak, K., Nelson, J. M., Nemes, D. B., Nie, M., Nigmatkulov, G., Niida, T., Nogach, L. V., Nonaka, T., Odyniec, G., Ogawa, A., Oh, K., Oh, S., Okorokov, V. A., Page, B. S., Pak, R., Panebratsev, Y., Pawlik, B., Pawlowska, D., Pei, H., Perkins, C., Pintér, R. L., Pluta, J., Porter, J., Posik, M., Pruthi, N. K., Przybycien, M., Putschke, J., Quintero, A., Radhakrishnan, S. K., Ramachandran, S., Ray, R. L., Reed, R., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ruan, L., Rusnak, J., Rusnakova, O., Sahoo, N. R., Sahu, P. K., Salur, S., Sandweiss, J., Schambach, J., Schmidke, W. B., Schmitz, N., Schweid, B. R., Seck, F., Seger, J., Sergeeva, M., Seto, R., Seyboth, P., Shah, N., Shahaliev, E., Shanmuganathan, P. V., Shao, M., Shen, F., Shen, W. Q., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Siejka, S., Sikora, R., Simko, M., Singh, J., Singha, S., Smirnov, D., Smirnov, N., Solyst, W., Sorensen, P., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Stefaniak, M., Stewart, D. J., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Sugiura, T., Sumbera, M., Summa, B., Sun, X. M., Sun, Y., Surrow, B., Svirida, D. N., Szymanski, P., Tang, A. H., Tang, Z., Taranenko, A., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Tlusty, D., Todoroki, T., Tokarev, M., Tomkiel, C. A., Trentalange, S., Tribble, R. E., Tribedy, P., Tripathy, S. K., Tsai, O. D., Tu, B., Ullrich, T., Underwood, D. G., Upsal, I., Van Buren, G., Vanek, J., Vasiliev, A. N., Vassiliev, I., Videbæk, F., Vokal, S., Voloshin, S. A., Wang, F., Wang, G., Wang, P., Wang, Y., Webb, J. C., Wen, L., Westfall, G. D., Wieman, H., Wissink, S. W., Witt, R., Wu, Y., Xiao, Z. G., Xie, G., Xie, W., Xu, H., Xu, N., Xu, Q. H., Xu, Y. F., Xu, Z., Yang, C., Yang, Q., Yang, S., Yang, Y., Ye, Z., Yi, L., Yip, K., Yu, N., Yoo, I. -K., Zbroszczyk, H., Zha, W., Zhang, D., Zhang, L., Zhang, S., Zhang, X. P., Zhang, Y., Zhang, Z., Zhao, J., Zhong, C., Zhou, C., Zhu, X., Zhu, Z., Zurek, M., and Zyzak, M.

Subjects
Nuclear Experiment, High Energy Physics - Experiment, Nuclear Theory
Abstract

We report the energy dependence of mid-rapidity (anti-)deuteron production in Au+Au collisions at $\sqrt{s_\text{NN}} =\ $7.7, 11.5, 14.5, 19.6, 27, 39, 62.4, and 200 GeV, measured by the STAR experiment at RHIC. The yield of deuterons is found to be well described by the thermal model. The collision energy, centrality, and transverse momentum dependence of the coalescence parameter $B_2$ are discussed. We find that the values of $B_2$ for anti-deuterons are systematically lower than those for deuterons, indicating that the correlation volume of anti-baryons is larger than that of baryons at $\sqrt{s_\text{NN}}$ from 19.6 to 39 GeV. In addition, values of $B_2$ are found to vary with collision energy and show a broad minimum around $\sqrt{s_\text{NN}}=\ $20 to 40 GeV, which might imply a change of the equation of state of the medium in these collisions., Comment: 12 pages, 13 figures, submitted to Phys. Rev. C

Published
2019
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36. Collision energy dependence of second-order off-diagonal and diagonal cumulants of net-charge, net-proton and net-kaon multiplicity distributions in Au+Au collisions

Author

STAR Collaboration, Adam, J., Adamczyk, L., Adams, J. R., Adkins, J. K., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alekseev, I., Anderson, D. M., Aoyama, R., Aparin, A., Arkhipkin, D., Aschenauer, E. C., Ashraf, M. U., Atetalla, F., Attri, A., Averichev, G. S., Bairathi, V., Barish, K., Bassill, A. J., Behera, A., Bellwied, R., Bhasin, A., Bhati, A. K., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Brandenburg, J. D., Brandin, A. V., Bryslawskyj, J., Bunzarov, I., Butterworth, J., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Chakaberia, I., Chaloupka, P., Chan, B. K., Chang, F-H., Chang, Z., Chankova-Bunzarova, N., Chatterjee, A., Chattopadhyay, S., Chen, J. H., Chen, X., Cheng, J., Cherney, M., Christie, W., Crawford, H. J., Csanád, M., Das, S., Dedovich, T. G., Deppner, I. M., Derevschikov, A. A., Didenko, L., Dilks, C., Dong, X., Drachenberg, J. L., Dunlop, J. C., Edmonds, T., Elsey, N., Engelage, J., Eppley, G., Esha, R., Esumi, S., Evdokimov, O., Ewigleben, J., Eyser, O., Fatemi, R., Fazio, S., Federic, P., Fedorisin, J., Feng, Y., Filip, P., Finch, E., Fisyak, Y., Fulek, L., Gagliardi, C. A., Galatyuk, T., Geurts, F., Gibson, A., Grosnick, D., Gupta, A., Guryn, W., Hamad, A. I., Hamed, A., Harris, J. W., He, L., Heppelmann, S., Herrmann, N., Holub, L., Hong, Y., Horvat, S., Huang, B., Huang, H. Z., Huang, S. L., Huang, T., Huang, X., Humanic, T. J., Huo, P., Igo, G., Jacobs, W. W., Jentsch, A., Jia, J., Jiang, K., Jowzaee, S., Ju, X., Judd, E. G., Kabana, S., Kagamaster, S., Kalinkin, D., Kang, K., Kapukchyan, D., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kelsey, M., Khyzhniak, Y. V., Kikoła, D. P., Kim, C., Kinghorn, T. A., Kisel, I., Kisiel, A., Kocan, M., Kochenda, L., Kosarzewski, L. K., Kramarik, L., Kravtsov, P., Krueger, K., Mudiyanselage, N. Kulathunga, Kumar, L., Elayavalli, R. Kunnawalkam, Kwasizur, J. H., Lacey, R., Landgraf, J. M., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Li, C., Li, W., Li, X., Li, Y., Liang, Y., Licenik, R., Lin, T., Lipiec, A., Lisa, M. A., Liu, F., Liu, H., Liu, P., Liu, T., Liu, X., Liu, Y., Liu, Z., Ljubicic, T., Llope, W. J., Lomnitz, M., Longacre, R. S., Luo, S., Luo, X., Ma, G. L., Ma, L., Ma, R., Ma, Y. G., Magdy, N., Majka, R., Mallick, D., Margetis, S., Markert, C., Matis, H. S., Matonoha, O., Mazer, J. A., Meehan, K., Mei, J. C., Minaev, N. G., Mioduszewski, S., Mishra, D., Mohanty, B., Mondal, M. M., Mooney, I., Moravcova, Z., Morozov, D. A., Nasim, Md., Nayak, K., Nelson, J. M., Nemes, D. B., Nie, M., Nigmatkulov, G., Niida, T., Nogach, L. V., Nonaka, T., Odyniec, G., Ogawa, A., Oh, K., Oh, S., Okorokov, V. A., Page, B. S., Pak, R., Panebratsev, Y., Pawlik, B., Pawlowska, D., Pei, H., Perkins, C., Pintér, R. L., Pluta, J., Porter, J., Posik, M., Pruthi, N. K., Przybycien, M., Putschke, J., Quintero, A., Radhakrishnan, S. K., Ramachandran, S., Ray, R. L., Reed, R., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ruan, L., Rusnak, J., Rusnakova, O., Sahoo, N. R., Sahu, P. K., Salur, S., Sandweiss, J., Schambach, J., Schmidke, W. B., Schmitz, N., Schweid, B. R., Seck, F., Seger, J., Sergeeva, M., Seto, R., Seyboth, P., Shah, N., Shahaliev, E., Shanmuganathan, P. V., Shao, M., Shen, F., Shen, W. Q., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Siejka, S., Sikora, R., Simko, M., Singh, J, Singha, S., Smirnov, D., Smirnov, N., Solyst, W., Sorensen, P., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Stefaniak, M., Stewart, D. J., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Sugiura, T., Sumbera, M., Summa, B., Sun, X. M., Sun, Y., Surrow, B., Svirida, D. N., Szymanski, P., Tang, A. H., Tang, Z., Taranenko, A., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Tlusty, D., Todoroki, T., Tokarev, M., Tomkiel, C. A., Trentalange, S., Tribble, R. E., Tribedy, P., Tripathy, S. K., Tsai, O. D., Tu, B., Ullrich, T., Underwood, D. G., Upsal, I., Van Buren, G., Vanek, J., Vasiliev, A. N., Vassiliev, I., Videbæk, F., Vokal, S., Voloshin, S. A., Wang, F., Wang, G., Wang, P., Wang, Y., Webb, J. C., Wen, L., Westfall, G. D., Wieman, H., Wissink, S. W., Witt, R., Wu, Y., Xiao, Z. G., Xie, G., Xie, W., Xu, H., Xu, N., Xu, Q. H., Xu, Y. F., Xu, Z., Yang, C., Yang, Q., Yang, S., Yang, Y., Ye, Z., Yi, L., Yip, K., Yoo, I. -K., Zbroszczyk, H., Zha, W., Zhang, D., Zhang, L., Zhang, S., Zhang, X. P., Zhang, Y., Zhang, Z., Zhao, J., Zhong, C., Zhou, C., Zhu, X., Zhu, Z., Zurek, M., and Zyzak, M.

Subjects
Nuclear Experiment, High Energy Physics - Experiment, High Energy Physics - Phenomenology
Abstract

We report the first measurements of a complete second-order cumulant matrix of net-charge, net-proton, and net-kaon multiplicity distributions for the first phase of the beam energy scan program at RHIC. This includes the centrality and, for the first time, the pseudorapidity window dependence of both diagonal and off-diagonal cumulants in Au+Au collisions at \sNN~= 7.7-200 GeV. Within the available acceptance of $|\eta|<0.5$, the cumulants grow linearly with the pseudorapidity window. Relative to the corresponding measurements in peripheral collisions, the ratio of off-diagonal over diagonal cumulants in central collisions indicates an excess correlation between net-charge and net-kaon, as well as between net-charge and net-proton. The strength of such excess correlation increases with the collision energy. The correlation between net-proton and net-kaon multiplicity distributions is observed to be negative at \sNN~= 200 GeV and change to positive at the lowest collision energy. Model calculations based on non-thermal (UrQMD) and thermal (HRG) production of hadrons cannot explain the data. These measurements will help map the QCD phase diagram, constrain hadron resonance gas model calculations, and provide new insights on the energy dependence of baryon-strangeness correlations. An erratum has been added to address the issue of self-correlation in the previously considered efficiency correction for off-diagonal cumulant measurement. Previously considered unidentified (net-)charge correlation results ($\sigma^{11}_{Q,p}$ and $\sigma^{11}_{Q,k})$ are now replaced with identified (net-)charge correlation ($\sigma^{11}_{Q^{PID},p}$ and $\sigma^{11}_{Q^{PID},k}$), Comment: Erratum: Phys. Rev. C 105, 029901 (10.1103/PhysRevC.105.029901)

Published
2019
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37. Azimuthal harmonics in small and large collision systems at RHIC top energies

Author

STAR Collaboration, Adam, J., Adamczyk, L., Adams, J. R., Adkins, J. K., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alekseev, I., Anderson, D. M., Aoyama, R., Aparin, A., Arkhipkin, D., Aschenauer, E. C., Ashraf, M. U., Atetalla, F., Attri, A., Averichev, G. S., Bairathi, V., Barish, K., Bassill, A. J., Behera, A., Bellwied, R., Bhasin, A., Bhati, A. K., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Brandenburg, J. D., Brandin, A. V., Bryslawskyj, J., Bunzarov, I., Butterworth, J., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Chakaberia, I., Chaloupka, P., Chan, B. K., Chang, F-H., Chang, Z., Chankova-Bunzarova, N., Chatterjee, A., Chattopadhyay, S., Chen, J. H., Chen, X., Cheng, J., Cherney, M., Christie, W., Crawford, H. J., Csanád, M., Das, S., Dedovich, T. G., Deppner, I. M., Derevschikov, A. A., Didenko, L., Dilks, C., Dong, X., Drachenberg, J. L., Dunlop, J. C., Edmonds, T., Elsey, N., Engelage, J., Eppley, G., Esha, R., Esumi, S., Evdokimov, O., Ewigleben, J., Eyser, O., Fatemi, R., Fazio, S., Federic, P., Fedorisin, J., Feng, Y., Filip, P., Finch, E., Fisyak, Y., Fulek, L., Gagliardi, C. A., Galatyuk, T., Geurts, F., Gibson, A., Grosnick, D., Gupta, A., Guryn, W., Hamad, A. I., Hamed, A., Harris, J. W., He, L., Heppelmann, S., Herrmann, N., Holub, L., Hong, Y., Horvat, S., Huang, B., Huang, H. Z., Huang, S. L., Huang, T., Huang, X., Humanic, T. J., Huo, P., Igo, G., Jacobs, W. W., Jentsch, A., Jia, J., Jiang, K., Jowzaee, S., Ju, X., Judd, E. G., Kabana, S., Kagamaster, S., Kalinkin, D., Kang, K., Kapukchyan, D., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kelsey, M., Khyzhniak, Y. V., Kikoła, D. P., Kim, C., Kinghorn, T. A., Kisel, I., Kisiel, A., Kocan, M., Kochenda, L., Kosarzewski, L. K., Kramarik, L., Kravtsov, P., Krueger, K., Mudiyanselage, N. Kulathunga, Kumar, L., Elayavalli, R. Kunnawalkam, Kwasizur, J. H., Lacey, R., Landgraf, J. M., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Li, C., Li, W., Li, X., Li, Y., Liang, Y., Licenik, R., Lin, T., Lipiec, A., Lisa, M. A., Liu, F., Liu, H., Liu, P., Liu, X., Liu, Y., Liu, Z., Ljubicic, T., Llope, W. J., Lomnitz, M., Longacre, R. S., Luo, S., Luo, X., Ma, G. L., Ma, L., Ma, R., Ma, Y. G., Magdy, N., Majka, R., Mallick, D., Margetis, S., Markert, C., Matis, H. S., Matonoha, O., Mazer, J. A., Meehan, K., Mei, J. C., Minaev, N. G., Mioduszewski, S., Mishra, D., Mohanty, B., Mondal, M. M., Mooney, I., Moravcova, Z., Morozov, D. A., Nasim, Md., Nayak, K., Nelson, J. M., Nemes, D. B., Nie, M., Nigmatkulov, G., Niida, T., Nogach, L. V., Nonaka, T., Odyniec, G., Ogawa, A., Oh, K., Oh, S., Okorokov, V. A., Page, B. S., Pak, R., Panebratsev, Y., Pawlik, B., Pei, H., Perkins, C., Pintér, R. L., Pluta, J., Porter, J., Posik, M., Pruthi, N. K., Przybycien, M., Putschke, J., Quintero, A., Radhakrishnan, S. K., Ramachandran, S., Ray, R. L., Reed, R., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ruan, L., Rusnak, J., Rusnakova, O., Sahoo, N. R., Sahu, P. K., Salur, S., Sandweiss, J., Schambach, J., Schmidke, W. B., Schmitz, N., Schweid, B. R., Seck, F., Seger, J., Sergeeva, M., Seto, R., Seyboth, P., Shah, N., Shahaliev, E., Shanmuganathan, P. V., Shao, M., Shen, F., Shen, W. Q., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Siejka, S., Sikora, R., Simko, M., Singh, J, Singha, S., Smirnov, D., Smirnov, N., Solyst, W., Sorensen, P., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Stewart, D. J., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Sugiura, T., Sumbera, M., Summa, B., Sun, X. M., Sun, Y., Surrow, B., Svirida, D. N., Szymanski, P., Tang, A. H., Tang, Z., Taranenko, A., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Todoroki, T., Tokarev, M., Tomkiel, C. A., Trentalange, S., Tribble, R. E., Tribedy, P., Tripathy, S. K., Tsai, O. D., Tu, B., Ullrich, T., Underwood, D. G., Upsal, I., Van Buren, G., Vanek, J., Vasiliev, A. N., Vassiliev, I., Videbæk, F., Vokal, S., Voloshin, S. A., Wang, F., Wang, G., Wang, P., Wang, Y., Webb, J. C., Wen, L., Westfall, G. D., Wieman, H., Wissink, S. W., Witt, R., Wu, Y., Xiao, Z. G., Xie, G., Xie, W., Xu, H., Xu, N., Xu, Q. H., Xu, Y. F., Xu, Z., Yang, C., Yang, Q., Yang, S., Yang, Y., Ye, Z., Yi, L., Yip, K., Yoo, I. -K., Zbroszczyk, H., Zha, W., Zhang, D., Zhang, L., Zhang, S., Zhang, X. P., Zhang, Y., Zhang, Z., Zhao, J., Zhong, C., Zhou, C., Zhu, X., Zhu, Z., Zurek, M., and Zyzak, M.

Subjects
Nuclear Experiment, Nuclear Theory
Abstract

The first ($v_1^{\text{even}}$), second ($v_2$) and third ($v_3$) harmonic coefficients of the azimuthal particle distribution at mid-rapidity, are extracted for charged hadrons and studied as a function of transverse momentum ($p_T$) and mean charged particle multiplicity density $\langle \mathrm{N_{ch}} \rangle$ in U+U ($\roots =193$~GeV), Au+Au, Cu+Au, Cu+Cu, $d$+Au and $p$+Au collisions at $\roots = 200$~GeV with the STAR Detector. For the same $\langle \mathrm{N_{ch}} \rangle$, the $v_1^{\text{even}}$ and $v_3$ coefficients are observed to be independent of collision system, while $v_2$ exhibits such a scaling only when normalized by the initial-state eccentricity ($\varepsilon_2$). The data also show that $\ln(v_2/\varepsilon_2)$ scales linearly with $\langle \mathrm{N_{ch}} \rangle^{-1/3}$. These measurements provide insight into initial-geometry fluctuations and the role of viscous hydrodynamic attenuation on $v_n$ from small to large collision systems.

Published
2019
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38. Collision Energy Dependence of $p_{\rm t}$ Correlations in Au+Au Collisions at RHIC

Author

STAR Collaboration, Adam, J., Adamczyk, L., Adams, J. R., Adkins, J. K., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alekseev, I., Anderson, D. M., Aoyama, R., Aparin, A., Arkhipkin, D., Aschenauer, E. C., Ashraf, M. U., Atetalla, F., Attri, A., Averichev, G. S., Bairathi, V., Barish, K., Bassill, A. J., Behera, A., Bellwied, R., Bhasin, A., Bhati, A. K., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Brandenburg, J. D., Brandin, A. V., Bryslawskyj, J., Bunzarov, I., Butterworth, J., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Chakaberia, I., Chaloupka, P., Chan, B. K., Chang, F-H., Chang, Z., Chankova-Bunzarova, N., Chatterjee, A., Chattopadhyay, S., Chen, J. H., Chen, X., Cheng, J., Cherney, M., Christie, W., Crawford, H. J., Csanad, M., Das, S., Dedovich, T. G., Deppner, I. M., Derevschikov, A. A., Didenko, L., Dilks, C., Dong, X., Drachenberg, J. L., Dunlop, J. C., Edmonds, T., Elsey, N., Engelage, J., Eppley, G., Esha, R., Esumi, S., Evdokimov, O., Ewigleben, J., Eyser, O., Fatemi, R., Fazio, S., Federic, P., Fedorisin, J., Feng, Y., Filip, P., Finch, E., Fisyak, Y., Fulek, L., Gagliardi, C. A., Galatyuk, T., Geurts, F., Gibson, A., Grosnick, D., Gupta, A., Guryn, W., Hamad, A. I., Hamed, A., Harris, J. W., He, L., Heppelmann, S., Herrmann, N., Holub, L., Hong, Y., Horvat, S., Huang, B., Huang, H. Z., Huang, S. L., Huang, T., Huang, X., Humanic, T. J., Huo, P., Igo, G., Jacobs, W. W., Jentsch, A., Jia, J., Jiang, K., Jowzaee, S., Ju, X., Judd, E. G., Kabana, S., Kagamaster, S., Kalinkin, D., Kang, K., Kapukchyan, D., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kelsey, M., Kikoła, D. P., Kim, C., Kinghorn, T. A., Kisel, I., Kisiel, A., Kocan, M., Kochenda, L., Kosarzewski, L. K., Kramarik, L., Kravtsov, P., Krueger, K., Mudiyanselage, N. Kulathunga, Kumar, L., Elayavalli, R. Kunnawalkam, Kwasizur, J. H., Lacey, R., Landgraf, J. M., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Li, C., Li, W., Li, X., Li, Y., Liang, Y., Licenik, R., Lin, T., Lipiec, A., Lisa, M. A., Liu, F., Liu, H., Liu, P., Liu, X., Liu, Y., Liu, Z., Ljubicic, T., Llope, W. J., Lomnitz, M., Longacre, R. S., Luo, S., Luo, X., Ma, G. L., Ma, L., Ma, R., Ma, Y. G., Magdy, N., Majka, R., Mallick, D., Margetis, S., Markert, C., Matis, H. S., Matonoha, O., Mazer, J. A., Meehan, K., Mei, J. C., Minaev, N. G., Mioduszewski, S., Mishra, D., Mohanty, B., Mondal, M. M., Mooney, I., Moravcova, Z., Morozov, D. A., Nasim, Md., Nayak, K., Nelson, J. M., Nemes, D. B., Nie, M., Nigmatkulov, G., Niida, T., Nogach, L. V., Nonaka, T., Odyniec, G., Ogawa, A., Oh, K., Oh, S., Okorokov, V. A., Page, B. S., Pak, R., Panebratsev, Y., Pawlik, B., Pei, H., Perkins, C., Pinter, R. L., Pluta, J., Porter, J., Posik, M., Pruthi, N. K., Przybycien, M., Putschke, J., Quintero, A., Radhakrishnan, S. K., Ramachandran, S., Ray, R. L., Reed, R., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ruan, L., Rusnak, J., Rusnakova, O., Sahoo, N. R., Sahu, P. K., Salur, S., Sandweiss, J., Schambach, J., Schmidke, W. B., Schmitz, N., Schweid, B. R., Seck, F., Seger, J., Sergeeva, M., Seto, R., Seyboth, P., Shah, N., Shahaliev, E., Shanmuganathan, P. V., Shao, M., Shen, F., Shen, W. Q., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Siejka, S., Sikora, R., Simko, M., Singh, J, Singha, S., Smirnov, D., Smirnov, N., Solyst, W., Sorensen, P., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Stewart, D. J., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Sugiura, T., Sumbera, M., Summa, B., Sun, X. M., Sun, Y., Surrow, B., Svirida, D. N., Szymanski, P., Tang, A. H., Tang, Z., Taranenko, A., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Todoroki, T., Tokarev, M., Tomkiel, C. A., Trentalange, S., Tribble, R. E., Tribedy, P., Tripathy, S. K., Tsai, O. D., Tu, B., Ullrich, T., Underwood, D. G., Upsal, I., Van Buren, G., Vanek, J., Vasiliev, A. N., Vassiliev, I., Videbæk, F., Vokal, S., Voloshin, S. A., Wang, F., Wang, G., Wang, P., Wang, Y., Webb, J. C., Wen, L., Westfall, G. D., Wieman, H., Wissink, S. W., Witt, R., Wu, Y., Xiao, Z. G., Xie, G., Xie, W., Xu, H., Xu, N., Xu, Q. H., Xu, Y. F., Xu, Z., Yang, C., Yang, Q., Yang, S., Yang, Y., Ye, Z., Yi, L., Yip, K., Yoo, I. -K., Zbroszczyk, H., Zha, W., Zhang, D., Zhang, L., Zhang, S., Zhang, X. P., Zhang, Y., Zhang, Z., Zhao, J., Zhong, C., Zhou, C., Zhu, X., Zhu, Z., Zurek, M. K., and Zyzak, M.

Subjects
Nuclear Experiment
Abstract

We present two-particle $p_{\rm t}$ correlations as a function of event centrality for Au+Au collisions at $\sqrt{s_{\rm NN}}$ = 7.7, 11.5, 14.5, 19.6, 27, 39, 62.4, and 200 GeV at the Relativistic Heavy Ion Collider using the STAR detector. These results are compared to previous measurements from CERES at the Super Proton Synchrotron and from ALICE at the Large Hadron Collider. The data are compared with UrQMD model calculations and with a model based on a Boltzmann-Langevin approach incorporating effects from thermalization. The relative dynamical correlations for Au+Au collisions at $\sqrt{s_{\rm NN}}$ = 200 GeV show a power law dependence on the number of participant nucleons and agree with the results for Pb+Pb collisions at $\sqrt{s_{\rm NN}} = 2.76~ {\rm TeV}$ from ALICE. As the collision energy is lowered from $\sqrt{s_{\rm NN}}$ = 200 GeV to 7.7 GeV, the centrality dependence of the relative dynamical correlations departs from the power law behavior observed at the higher collision energies. In central collisions, the relative dynamical correlations increase with collision energy up to $\sqrt{s_{\rm NN}}$ = 200 GeV in contrast to previous measurements that showed little dependence on the collision energy., Comment: 7 pages, 6 figures

Published
2019
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39. Long term durability test and post mortem for metal-supported solid oxide electrolysis cells

Author

Shen, F, Wang, R, and Tucker, MC

Subjects
Energy, Chemical Sciences, Engineering
Abstract

Hydrogen is a renewable energy carrier, and electrolysis to split water is the most environmentally friendly method to produce hydrogen. This work reports long-term durability and degradation mode analysis for metal-supported solid oxide electrolysis cells (MS-SOECs). Catalyst screening showed that MS-SOECs with composite electrode catalysts (samarium-doped ceria-nickel [SDC-Ni] serving as a fuel electrode catalyst, and praseodymium oxide [PrOx]-SDC or La0.6Sr0.4Co0.2Fe0.8O3 [LSCF]-SDC serving as an air electrode catalyst) exhibit the highest electrochemical performance at 700 °C. The degradation rate of cells with LSCF-SDC as the air electrode catalyst was as low as 1.3%/100 h in long term durability tests at a current density of 0.33 A cm−2, in contrast to rapid degradation observed for a cell with a PrOx-SDC air electrode. Post-mortem analysis reveals the degradation is dependent on the primary modes of fuel electrode catalyst coarsening and Cr poisoning on the air electrode catalyst, as well as secondary modes of oxidation of the metal support and local elemental accumulation of Ni. Other degradation modes reported in conventional anode-supported SOECs, such as Ni migration, foreign element contamination, delamination of the cell, and nano-voids on the electrolyte, are not observed in the present MS-SOECs.

Published
2020

40. Centrality and transverse momentum dependence of $D^0$-meson production at mid-rapidity in Au+Au collisions at ${\sqrt{s_{\rm NN}} = \rm{200\,GeV}}$

Author

STAR Collaboration, Adam, J., Adamczyk, L., Adams, J. R., Adkins, J. K., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alekseev, I., Anderson, D. M., Aoyama, R., Aparin, A., Arkhipkin, D., Aschenauer, E. C., Ashraf, M. U., Atetalla, F., Attri, A., Averichev, G. S., Bairathi, V., Barish, K., Bassill, A. J., Behera, A., Bellwied, R., Bhasin, A., Bhati, A. K., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Brandenburg, J. D., Brandin, A. V., Brown, D., Bryslawskyj, J., Bunzarov, I., Butterworth, J., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Chakaberia, I., Chaloupka, P., Chan, B. K., Chang, F-H., Chang, Z., Chankova-Bunzarova, N., Chatterjee, A., Chattopadhyay, S., Chen, J. H., Chen, X., Cheng, J., Cherney, M., Christie, W., Contin, G., Crawford, H. J., Csanad, M., Das, S., Dedovich, T. G., Deppner, I. M., Derevschikov, A. A., Didenko, L., Dilks, C., Dong, X., Drachenberg, J. L., Dunlop, J. C., Edmonds, T., Efimov, L. G., Elsey, N., Engelage, J., Eppley, G., Esha, R., Esumi, S., Evdokimov, O., Ewigleben, J., Eyser, O., Fatemi, R., Fazio, S., Federic, P., Fedorisin, J., Feng, Y., Filip, P., Finch, E., Fisyak, Y., Flores, C. E., Fulek, L., Gagliardi, C. A., Galatyuk, T., Geurts, F., Gibson, A., Greiner, L., Grosnick, D., Gupta, A., Guryn, W., Hamad, A. I., Hamed, A., Harlenderova, A., Harris, J. W., He, L., Heppelmann, S., Herrmann, N., Holub, L., Hong, Y., Horvat, S., Huang, B., Huang, H. Z., Huang, S. L., Huang, T., Huang, X., Humanic, T. J., Huo, P., Igo, G., Jacobs, W. W., Jentsch, A., Jia, J., Jiang, K., Jowzaee, S., Ju, X., Judd, E. G., Kabana, S., Kagamaster, S., Kalinkin, D., Kang, K., Kapukchyan, D., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kelsey, M., Kikoła, D. P., Kim, C., Kinghorn, T. A., Kisel, I., Kisiel, A., Kocan, M., Kochenda, L., Kosarzewski, L. K., Kramarik, L., Kravtsov, P., Krueger, K., Mudiyanselage, N. Kulathunga, Kumar, L., Elayavalli, R. Kunnawalkam, Kvapil, J., Kwasizur, J. H., Lacey, R., Landgraf, J. M., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Li, C., Li, W., Li, X., Li, Y., Liang, Y., Licenik, R., Lidrych, J., Lin, T., Lipiec, A., Lisa, M. A., Liu, F., Liu, H., Liu, P., Liu, X., Liu, Y., Liu, Z., Ljubicic, T., Llope, W. J., Lomnitz, M., Longacre, R. S., Luo, S., Luo, X., Ma, G. L., Ma, L., Ma, R., Ma, Y. G., Magdy, N., Majka, R., Mallick, D., Margetis, S., Markert, C., Matis, H. S., Matonoha, O., Mazer, J. A., Meehan, K., Mei, J. C., Minaev, N. G., Mioduszewski, S., Mishra, D., Mohanty, B., Mondal, M. M., Mooney, I., Moravcova, Z., Morozov, D. A., Mustafa, M. K., Nasim, Md., Nayak, K., Nelson, J. M., Nemes, D. B., Nie, M., Nigmatkulov, G., Niida, T., Nogach, L. V., Nonaka, T., Odyniec, G., Ogawa, A., Oh, K., Oh, S., Okorokov, V. A., Page, B. S., Pak, R., Panebratsev, Y., Pawlik, B., Pei, H., Perkins, C., Pinter, R. L., Pluta, J., Porter, J., Posik, M., Pruthi, N. K., Przybycien, M., Putschke, J., Quintero, A., Qiu, H., Radhakrishnan, S. K., Ramachandran, S., Ray, R. L., Reed, R., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ruan, L., Rusnak, J., Rusnakova, O., Sahoo, N. R., Sahu, P. K., Salur, S., Sandweiss, J., Schambach, J., Schmah, A. M., Schmidke, W. B., Schmitz, N., Schweid, B. R., Seck, F., Seger, J., Sergeeva, M., Seto, R., Seyboth, P., Shah, N., Shahaliev, E., Shanmuganathan, P. V., Shao, M., Shen, F., Shen, W. Q., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Siejka, S., Sikora, R., Simko, M., Singh, J, Singha, S., Smirnov, D., Smirnov, N., Solyst, W., Sorensen, P., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Stewart, D. J., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Sugiura, T., Sumbera, M., Summa, B., Sun, X. M., Sun, Y., Surrow, B., Svirida, D. N., Szelezniak, M., Szymanski, P., Tang, A. H., Tang, Z., Taranenko, A., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Todoroki, T., Tokarev, M., Tomkiel, C. A., Trentalange, S., Tribble, R. E., Tribedy, P., Tripathy, S. K., Tsai, O. D., Tu, B., Ullrich, T., Underwood, D. G., Upsal, I., Van Buren, G., Vanek, J., Vasiliev, A. N., Vassiliev, I., Videbæk, F., Vokal, S., Voloshin, S. A., Vossen, A., Wang, F., Wang, G., Wang, P., Wang, Y., Webb, J. C., Wen, L., Westfall, G. D., Wieman, H., Wissink, S. W., Witt, R., Wu, Y., Xiao, Z. G., Xie, G., Xie, W., Xu, H., Xu, N., Xu, Q. H., Xu, Y. F., Xu, Z., Yang, C., Yang, Q., Yang, S., Yang, Y., Ye, Z., Yi, L., Yip, K., Yoo, I. -K., Zbroszczyk, H., Zha, W., Zhang, D., Zhang, J., Zhang, L., Zhang, S., Zhang, X. P., Zhang, Y., Zhang, Z., Zhao, J., Zhong, C., Zhou, C., Zhu, X., Zhu, Z., Zurek, M. K., and Zyzak, M.

Subjects
Nuclear Experiment, High Energy Physics - Experiment
Abstract

We report a new measurement of $D^0$-meson production at mid-rapidity ($|y|$\,$<$\,1) in Au+Au collisions at ${\sqrt{s_{\rm NN}} = \rm{200\,GeV}}$ utilizing the Heavy Flavor Tracker, a high resolution silicon detector at the STAR experiment. Invariant yields of $D^0$-mesons with transverse momentum $p_{T}$ $\lesssim 9$\,GeV/$c$ are reported in various centrality bins (0--10\%, 10--20\%, 20--40\%, 40--60\% and 60--80\%). Blast-Wave thermal models are used to fit the $D^0$-meson $p_{T}$ spectra to study $D^0$ hadron kinetic freeze-out properties. The average radial flow velocity extracted from the fit is considerably smaller than that of light hadrons ($\pi,K$ and $p$), but comparable to that of hadrons containing multiple strange quarks ($\phi,\Xi^-$), indicating that $D^0$ mesons kinetically decouple from the system earlier than light hadrons. The calculated $D^0$ nuclear modification factors re-affirm that charm quarks suffer large amount of energy loss in the medium, similar to those of light quarks for $p_{T}$\,$>$\,4\,GeV/$c$ in central 0--10\% Au+Au collisions. At low $p_{T}$, the nuclear modification factors show a characteristic structure qualitatively consistent with the expectation from model predictions that charm quarks gain sizable collective motion during the medium evolution. The improved measurements are expected to offer new constraints to model calculations and help gain further insights into the hot and dense medium created in these collisions., Comment: 27 pages, 36 figures, submitted to PRC

Published
2018
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42. Measurements of Dielectron Production in Au$+$Au Collisions at $\sqrt{s_{NN}}$= 27, 39, and 62.4 GeV from the STAR Experiment

Author

STAR Collaboration, Adam, J., Adamczyk, L., Adams, J. R., Adkins, J. K., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alekseev, I., Anderson, D. M., Aoyama, R., Aparin, A., Arkhipkin, D., Aschenauer, E. C., Ashraf, M. U., Atetalla, F., Attri, A., Averichev, G. S., Bai, X., Bairathi, V., Barish, K., Bassill, A. J., Behera, A., Bellwied, R., Bhasin, A., Bhati, A. K., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Brandenburg, J. D., Brandin, A. V., Brown, D., Bryslawskyj, J., Bunzarov, I., Butterworth, J., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Chakaberia, I., Chaloupka, P., Chan, B. K., Chang, F-H., Chang, Z., Chankova-Bunzarova, N., Chatterjee, A., Chattopadhyay, S., Chen, J. H., Chen, X., Cheng, J., Cherney, M., Christie, W., Contin, G., Crawford, H. J., Csanad, M., Das, S., Dedovich, T. G., Deppner, I. M., Derevschikov, A. A., Didenko, L., Dilks, C., Dong, X., Drachenberg, J. L., Dunlop, J. C., Edmonds, T., Efimov, L. G., Elsey, N., Engelage, J., Eppley, G., Esha, R., Esumi, S., Evdokimov, O., Ewigleben, J., Eyser, O., Fatemi, R., Fazio, S., Federic, P., Fedorisin, J., Filip, P., Finch, E., Fisyak, Y., Flores, C. E., Fulek, L., Gagliardi, C. A., Galatyuk, T., Geurts, F., Gibson, A., Grosnick, D., Gunarathne, D. S., Guo, Y., Gupta, A., Guryn, W., Hamad, A. I., Hamed, A., Harlenderova, A., Harris, J. W., He, L., Heppelmann, S., Herrmann, N., Hirsch, A., Holub, L., Hong, Y., Horvat, S., Huang, B., Huang, H. Z., Huang, S. L., Huang, T., Huang, X., Humanic, T. J., Huo, P., Igo, G., Jacobs, W. W., Jentsch, A., Jia, J., Jiang, K., Jowzaee, S., Ju, X., Judd, E. G., Kabana, S., Kagamaster, S., Kalinkin, D., Kang, K., Kapukchyan, D., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kelsey, M., Kikoła, D. P., Kim, C., Kinghorn, T. A., Kisel, I., Kisiel, A., Kocan, M., Kochenda, L., Kosarzewski, L. K., Kraishan, A. F., Kramarik, L., Krauth, L., Kravtsov, P., Krueger, K., Kulathunga, N., Kumar, L., Elayavalli, R. Kunnawalkam, Kvapil, J., Kwasizur, J. H., Lacey, R., Landgraf, J. M., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Li, C., Li, W., Li, X., Li, Y., Liang, Y., Licenik, R., Lidrych, J., Lin, T., Lipiec, A., Lisa, M. A., Liu, F., Liu, H., Liu, P., Liu, X., Liu, Y., Liu, Z., Ljubicic, T., Llope, W. J., Lomnitz, M., Longacre, R. S., Luo, S., Luo, X., Ma, G. L., Ma, L., Ma, R., Ma, Y. G., Magdy, N., Majka, R., Mallick, D., Margetis, S., Markert, C., Matis, H. S., Matonoha, O., Mazer, J. A., Meehan, K., Mei, J. C., Minaev, N. G., Mioduszewski, S., Mishra, D., Mohanty, B., Mondal, M. M., Mooney, I., Moravcova, Z., Morozov, D. A., Nasim, Md., Nayak, K., Negrete, J. D., Nelson, J. M., Nemes, D. B., Nie, M., Nigmatkulov, G., Niida, T., Nogach, L. V., Nonaka, T., Odyniec, G., Ogawa, A., Oh, K., Oh, S., Okorokov, V. A., Olvitt Jr., D., Page, B. S., Pak, R., Panebratsev, Y., Pawlik, B., Pei, H., Perkins, C., Pinter, R. L., Pluta, J., Porter, J., Posik, M., Pruthi, N. K., Przybycien, M., Putschke, J., Quintero, A., Radhakrishnan, S. K., Ray, R. L., Reed, R., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ruan, L., Rusnak, J., Rusnakova, O., Sahoo, N. R., Sahu, P. K., Salur, S., Sandweiss, J., Schambach, J., Schmah, A. M., Schmidke, W. B., Schmitz, N., Schweid, B. R., Seck, F., Seger, J., Sergeeva, M., Seto, R., Seyboth, P., Shah, N., Shahaliev, E., Shanmuganathan, P. V., Shao, M., Shen, F., Shen, W. Q., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Siejka, S., Sikora, R., Simko, M., Singh, J, Singha, S., Smirnov, D., Smirnov, N., Solyst, W., Sorensen, P., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Stewart, D. J., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Sugiura, T., Sumbera, M., Summa, B., Sun, X. M., Sun, Y., Surrow, B., Svirida, D. N., Szymanski, P., Tang, A. H., Tang, Z., Taranenko, A., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Tlusty, D., Todoroki, T., Tokarev, M., Tomkiel, C. A., Trentalange, S., Tribble, R. E., Tribedy, P., Tripathy, S. K., Tsai, O. D., Tu, B., Ullrich, T., Underwood, D. G., Upsal, I., Van Buren, G., Vanek, J., Vasiliev, A. N., Vassiliev, I., Videbæk, F., Vokal, S., Voloshin, S. A., Vossen, A., Wang, F., Wang, G., Wang, P., Wang, Y., Webb, J. C., Wen, L., Westfall, G. D., Wieman, H., Wissink, S. W., Witt, R., Wu, Y., Xiao, Z. G., Xie, G., Xie, W., Xu, J., Xu, N., Xu, Q. H., Xu, Y. F., Xu, Z., Yang, C., Yang, Q., Yang, S., Yang, Y., Ye, Z., Yi, L., Yip, K., Yoo, I. -K., Zbroszczyk, H., Zha, W., Zhang, D., Zhang, J., Zhang, L., Zhang, S., Zhang, X. P., Zhang, Y., Zhang, Z., Zhao, J., Zhong, C., Zhou, C., Zhu, X., Zhu, Z., Zurek, M. K., and Zyzak, M.

Subjects
Nuclear Experiment
Abstract

We report systematic measurements of dielectron ($e^{\pm}e^{\pm}$) invariant-mass $M_{ee}$ spectra at mid-rapidity in Au+Au collisions at $\sqrt{s_{NN}}$ = 27, 39, and 62.4 GeV taken with the STAR detector at the Relativistic Heavy Ion Collider. For all energies studied, a significant excess yield of dielectrons is observed in the low-mass region (0.40$ < M_{ee} < 0.75$ MeV/$c^2$) compared to hadronic cocktail simulations at freeze-out. Models that include an in-medium broadening of the $\rho$-meson spectral function consistently describe the observed excess. In addition, we report acceptance-corrected dielectron-excess spectra for Au+Au collisions at mid-rapidity ($\left|y_{ee}\right|$ $<$ 1) in the 0$-$80% centrality bin for each collision energy. The integrated excess yields for $0.4 < M_{ee} < 0.75\ \textrm{GeV}/c^{2}$, normalized by the charged particle multiplicity at mid-rapidity, are compared with previously published measurements for Au+Au at $\sqrt{s_{NN}}$ = 19.6 and 200 GeV. The normalized excess yields in the low-mass region show no significant collision energy dependence. The data, however, are consistent with model calculations that demonstrate a modest energy dependence.

Published
2018

43. Erratum: Observation of $D^0$ meson nuclear modifications in Au+Au collisions at $\sqrt{s_{_{\mathrm{NN}}}}$ = 200 GeV

Author

STAR Collaboration, Adam, J., Adamczyk, L., Adams, J. R., Adkins, J. K., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alekseev, I., Anderson, D. M., Aoyama, R., Aparin, A., Arkhipkin, D., Aschenauer, E. C., Ashraf, M. U., Atetalla, F., Attri, A., Averichev, G. S., Bai, X., Bairathi, V., Barish, K., Bassill, A. J., Behera, A., Bellwied, R., Bhasin, A., Bhati, A. K., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Brandenburg, J. D., Brandin, A. V., Brown, D., Bryslawskyj, J., Bunzarov, I., Butterworth, J., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Chakaberia, I., Chaloupka, P., Chan, B. K., Chang, F-H., Chang, Z., Chankova-Bunzarova, N., Chatterjee, A., Chattopadhyay, S., Chen, J. H., Chen, X., Cheng, J., Cherney, M., Christie, W., Contin, G., Crawford, H. J., Csanad, M., Das, S., Dedovich, T. G., Deppner, I. M., Derevschikov, A. A., Didenko, L., Dilks, C., Dong, X., Drachenberg, J. L., Dunlop, J. C., Efimov, L. G., Elsey, N., Engelage, J., Eppley, G., Esha, R., Esumi, S., Evdokimov, O., Ewigleben, J., Eyser, O., Fatemi, R., Fazio, S., Federic, P., Fedorisin, J., Filip, P., Finch, E., Fisyak, Y., Flores, C. E., Fulek, L., Gagliardi, C. A., Galatyuk, T., Geurts, F., Gibson, A., Grosnick, D., Gunarathne, D. S., Guo, Y., Gupta, A., Guryn, W., Hamad, A. I., Hamed, A., Harlenderova, A., Harris, J. W., He, L., Heppelmann, S., Herrmann, N., Hirsch, A., Holub, L., Hong, Y., Horvat, S., Huang, B., Huang, H. Z., Huang, S. L., Huang, T., Huang, X., Humanic, T. J., Huo, P., Igo, G., Jacobs, W. W., Jentsch, A., Jia, J., Jiang, K., Jowzaee, S., Ju, X., Judd, E. G., Kabana, S., Kagamaster, S., Kalinkin, D., Kang, K., Kapukchyan, D., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kikoła, D. P., Kim, C., Kinghorn, T. A., Kisel, I., Kisiel, A., Kocan, M., Kochenda, L., Kosarzewski, L. K., Kraishan, A. F., Kramarik, L., Krauth, L., Kravtsov, P., Krueger, K., Kulathunga, N., Kumar, L., Elayavalli, R. Kunnawalkam, Kvapil, J., Kwasizur, J. H., Lacey, R., Landgraf, J. M., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Li, C., Li, W., Li, X., Li, Y., Liang, Y., Licenik, R., Lidrych, J., Lin, T., Lipiec, A., Lisa, M. A., Liu, F., Liu, H., Liu, P., Liu, Y., Liu, Z., Ljubicic, T., Llope, W. J., Lomnitz, M., Longacre, R. S., Luo, S., Luo, X., Ma, G. L., Ma, L., Ma, R., Ma, Y. G., Magdy, N., Majka, R., Mallick, D., Margetis, S., Markert, C., Matis, H. S., Matonoha, O., Mazer, J. A., Meehan, K., Mei, J. C., Minaev, N. G., Mioduszewski, S., Mishra, D., Mohanty, B., Mondal, M. M., Mooney, I., Moravcova, Z., Morozov, D. A., Nasim, Md., Nayak, K., Negrete, J. D., Nelson, J. M., Nemes, D. B., Nie, M., Nigmatkulov, G., Niida, T., Nogach, L. V., Nonaka, T., Odyniec, G., Ogawa, A., Oh, K., Oh, S., Okorokov, V. A., Olvitt Jr., D., Page, B. S., Pak, R., Panebratsev, Y., Pawlik, B., Pei, H., Perkins, C., Pinter, R. L., Pluta, J., Porter, J., Posik, M., Pruthi, N. K., Przybycien, M., Putschke, J., Quintero, A., Radhakrishnan, S. K., Ramachandran, S., Ray, R. L., Reed, R., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ruan, L., Rusnak, J., Rusnakova, O., Sahoo, N. R., Sahu, P. K., Salur, S., Sandweiss, J., Schambach, J., Schmah, A. M., Schmidke, W. B., Schmitz, N., Schweid, B. R., Seck, F., Seger, J., Sergeeva, M., Seto, R., Seyboth, P., Shah, N., Shahaliev, E., Shanmuganathan, P. V., Shao, M., Shen, F., Shen, W. Q., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Siejka, S., Sikora, R., Simko, M., Singh, J, Singha, S., Smirnov, D., Smirnov, N., Solyst, W., Sorensen, P., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Stewart, D. J., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Sugiura, T., Sumbera, M., Summa, B., Sun, X. M., Sun, Y., Surrow, B., Svirida, D. N., Szymanski, P., Tang, A. H., Tang, Z., Taranenko, A., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Tlusty, D., Todoroki, T., Tokarev, M., Tomkiel, C. A., Trentalange, S., Tribble, R. E., Tribedy, P., Tripathy, S. K., Tsai, O. D., Tu, B., Ullrich, T., Underwood, D. G., Upsal, I., Van Buren, G., Vanek, J., Vasiliev, A. N., Vassiliev, I., Videbæk, F., Vokal, S., Voloshin, S. A., Vossen, A., Wang, F., Wang, G., Wang, P., Wang, Y., Webb, J. C., Wen, L., Westfall, G. D., Wieman, H., Wissink, S. W., Witt, R., Wu, Y., Xiao, Z. G., Xie, G., Xie, W., Xu, J., Xu, N., Xu, Q. H., Xu, Y. F., Xu, Z., Yang, C., Yang, Q., Yang, S., Yang, Y., Ye, Z., Yi, L., Yip, K., Yoo, I. -K., Zbroszczyk, H., Zha, W., Zhang, J., Zhang, L., Zhang, S., Zhang, X. P., Zhang, Y., Zhang, Z., Zhao, J., Zhong, C., Zhou, C., Zhu, X., Zhu, Z., and Zyzak, M.

Subjects
Nuclear Experiment
Abstract

In this erratum we report changes on the $D^0$ $p_T$ spectra and nuclear modification factor ($R_{AA}$) in Au+Au collisions at $\sqrt{s_{_{\mathrm{NN}}}}$ = 200 GeV by fixing the errors in the efficiency and selection criteria that affected the Au+Au results. The p+p reference spectrum has changed as well and is updated with new fragmentation parameters., Comment: 5 pages, 3 figures, erratum for Phys. Rev. Lett. 113,142301 (2014)

Published
2018

44. Improved measurement of the longitudinal spin transfer to $\Lambda$ and $\bar \Lambda$ hyperons in polarized proton-proton collisions at $\sqrt s$ = 200 GeV

Author

Adam, J., Adamczyk, L., Adams, J. R., Adkins, J. K., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alekseev, I., Anderson, D. M., Aoyama, R., Aparin, A., Arkhipkin, D., Aschenauer, E. C., Ashraf, M. U., Atetalla, F., Attri, A., Averichev, G. S., Bai, X., Bairathi, V., Barish, K., Bassill, A. J., Behera, A., Bellwied, R., Bhasin, A., Bhati, A. K., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Brandenburg, J. D., Brandin, A. V., Brown, D., Bryslawskyj, J., Bunzarov, I., Butterworth, J., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Cendejas, R., Chakaberia, I., Chaloupka, P., Chan, B. K., Chang, F-H., Chang, Z., Chankova-Bunzarova, N., Chatterjee, A., Chattopadhyay, S., Chen, J. H., Chen, X., Cheng, J., Cherney, M., Christie, W., Contin, G., Crawford, H. J., Csanad, M., Das, S., Dedovich, T. G., Deng, J., Deppner, I. M., Derevschikov, A. A., Didenko, L., Dilks, C., Dong, X., Drachenberg, J. L., Dunlop, J. C., Efimov, L. G., Elsey, N., Engelage, J., Eppley, G., Esha, R., Esumi, S., Evdokimov, O., Ewigleben, J., Eyser, O., Fatemi, R., Fazio, S., Federic, P., Federicova, P., Fedorisin, J., Filip, P., Finch, E., Fisyak, Y., Flores, C. E., Fulek, L., Gagliardi, C. A., Galatyuk, T., Geurts, F., Gibson, A., Grosnick, D., Gunarathne, D. S., Guo, Y., Gupta, A., Guryn, W., Hamad, A. I., Hamed, A., Harlenderova, A., Harris, J. W., He, L., Heppelmann, S., Herrmann, N., Hirsch, A., Holub, L., Hong, Y., Horvat, S., Huang, B., Huang, H. Z., Huang, S. L., Huang, T., Huang, X., Humanic, T. J., Huo, P., Igo, G., Jacobs, W. W., Jentsch, A., Jia, J., Jiang, K., Jowzaee, S., Ju, X., Judd, E. G., Kabana, S., Kagamaster, S., Kalinkin, D., Kang, K., Kapukchyan, D., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kikoła, D. P., Kim, C., Kinghorn, T. A., Kisel, I., Kisiel, A., Kochenda, L., Kosarzewski, L. K., Kraishan, A. F., Kramarik, L., Krauth, L., Kravtsov, P., Krueger, K., Kulathunga, N., Kumar, L., Elayavalli, R. Kunnawalkam, Kvapil, J., Kwasizur, J. H., Lacey, R., Landgraf, J. M., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Li, C., Li, W., Li, X., Li, Y., Liang, Y., Lidrych, J., Lin, T., Lipiec, A., Lisa, M. A., Liu, F., Liu, H., Liu, P., Liu, Y., Liu, Z., Ljubicic, T., Llope, W. J., Lomnitz, M., Longacre, R. S., Luo, S., Luo, X., Ma, G. L., Ma, L., Ma, R., Ma, Y. G., Magdy, N., Majka, R., Mallick, D., Margetis, S., Markert, C., Matis, H. S., Matonoha, O., Mazer, J. A., Meehan, K., Mei, J. C., Minaev, N. G., Mioduszewski, S., Mishra, D., Mohanty, B., Mondal, M. M., Mooney, I., Morozov, D. A., Nasim, Md., Negrete, J. D., Nelson, J. M., Nemes, D. B., Nie, M., Nigmatkulov, G., Niida, T., Nogach, L. V., Nonaka, T., Odyniec, G., Ogawa, A., Oh, K., Oh, S., Okorokov, V. A., Olvitt Jr., D., Page, B. S., Pak, R., Panebratsev, Y., Pawlik, B., Pei, H., Perkins, C., Pinter, R. L., Pluta, J., Porter, J., Posik, M., Pruthi, N. K., Przybycien, M., Putschke, J., Quintero, A., Radhakrishnan, S. K., Ramachandran, S., Ray, R. L., Reed, R., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ruan, L., Rusnak, J., Rusnakova, O., Sahoo, N. R., Sahu, P. K., Salur, S., Sandweiss, J., Schambach, J., Schmah, A. M., Schmidke, W. B., Schmitz, N., Schweid, B. R., Seck, F., Seger, J., Sergeeva, M., Seto, R., Seyboth, P., Shah, N., Shahaliev, E., Shanmuganathan, P. V., Shao, M., Shen, F., Shen, W. Q., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Siejka, S., Sikora, R., Simko, M., Singh, J, Singha, S., Smirnov, D., Smirnov, N., Solyst, W., Sorensen, P., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Stewart, D. J., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Sugiura, T., Sumbera, M., Summa, B., Sun, X. M., Sun, X., Sun, Y., Surrow, B., Svirida, D. N., Szymanski, P., Tang, A. H., Tang, Z., Taranenko, A., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Tlusty, D., Todoroki, T., Tokarev, M., Tomkiel, C. A., Trentalange, S., Tribble, R. E., Tribedy, P., Tripathy, S. K., Tsai, O. D., Tu, B., Ullrich, T., Underwood, D. G., Upsal, I., Van Buren, G., Vanek, J., Vasiliev, A. N., Vassiliev, I., Videbæk, F., Vokal, S., Voloshin, S. A., Vossen, A., Wang, F., Wang, G., Wang, P., Wang, Y., Webb, J. C., Wen, L., Westfall, G. D., Wieman, H., Wissink, S. W., Witt, R., Wu, Y., Xiao, Z. G., Xie, G., Xie, W., Xu, J., Xu, N., Xu, Q. H., Xu, Y. F., Xu, Z., Yang, C., Yang, Q., Yang, S., Yang, Y., Ye, Z., Yi, L., Yip, K., Yoo, I. -K., Yu, N., Zbroszczyk, H., Zha, W., Zhang, J., Zhang, L., Zhang, S., Zhang, X. P., Zhang, Y., Zhang, Z., Zhao, J., Zhong, C., Zhou, C., Zhu, X., Zhu, Z., and Zyzak, M.

Subjects
High Energy Physics - Experiment
Abstract

The longitudinal spin transfer $D_{LL}$ to $\Lambda$ and $\bar{\Lambda}$ hyperons produced in high-energy polarized proton--proton collisions is expected to be sensitive to the helicity distribution functions of strange quarks and anti-quarks of the proton, and to longitudinally polarized fragmentation functions. We report an improved measurement of $D_{LL}$ from data obtained at a center-of-mass energy of $\sqrt{s}$ = 200 GeV with the STAR detector at RHIC. The data have an approximately twelve times larger figure-of-merit than prior results and cover $|\eta|<$ 1.2 in pseudo-rapidity with transverse momenta $p_T$ up to 6 GeV/c. In the forward scattering hemisphere at largest $p_T$, the longitudinal spin transfer is found to be $D_{LL}$ = -0.036 $\pm$ 0.048 (stat) $\pm$ 0.013(sys) for $\Lambda$ hyperons and $D_{LL}$ = 0.032 $\pm$ 0.043\,(stat) $\pm$ 0.013\,(sys) for $\bar{\Lambda}$ anti-hyperons. The dependences on $\eta$ and $p_T$ are presented and compared with model evaluations., Comment: 8 pages, 4 figures

Published
2018
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45. Transverse spin transfer to $\Lambda$ and $\bar{\Lambda}$ hyperons in polarized proton-proton collisions at $\sqrt{s}=200\,\mathrm{GeV}$

Author

STAR Collaboration, Adam, J., Adamczyk, L., Adams, J. R., Adkins, J. K., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alekseev, I., Anderson, D. M., Aoyama, R., Aparin, A., Arkhipkin, D., Aschenauer, E. C., Ashraf, M. U., Atetalla, F., Attri, A., Averichev, G. S., Bai, X., Bairathi, V., Barish, K., Bassill, A. J., Behera, A., Bellwied, R., Bhasin, A., Bhati, A. K., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Brandenburg, J. D., Brandin, A. V., Brown, D., Bryslawskyj, J., Bunzarov, I., Butterworth, J., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Chakaberia, I., Chaloupka, P., Chan, B. K., Chang, F-H., Chang, Z., Chankova-Bunzarova, N., Chatterjee, A., Chattopadhyay, S., Chen, J. H., Chen, X., Cheng, J., Cherney, M., Christie, W., Contin, G., Crawford, H. J., Csanad, M., Das, S., Dedovich, T. G., Deppner, I. M., Derevschikov, A. A., Didenko, L., Dilks, C., Dong, X., Drachenberg, J. L., Dunlop, J. C., Efimov, L. G., Elsey, N., Engelage, J., Eppley, G., Esha, R., Esumi, S., Evdokimov, O., Ewigleben, J., Eyser, O., Fatemi, R., Fazio, S., Federic, P., Federicova, P., Fedorisin, J., Filip, P., Finch, E., Fisyak, Y., Flores, C. E., Fulek, L., Gagliardi, C. A., Galatyuk, T., Geurts, F., Gibson, A., Grosnick, D., Gunarathne, D. S., Guo, Y., Gupta, A., Guryn, W., Hamad, A. I., Hamed, A., Harlenderova, A., Harris, J. W., He, L., Heppelmann, S., Herrmann, N., Hirsch, A., Holub, L., Hong, Y., Horvat, S., Huang, B., Huang, H. Z., Huang, S. L., Huang, T., Huang, X., Humanic, T. J., Huo, P., Igo, G., Jacobs, W. W., Jentsch, A., Jia, J., Jiang, K., Jowzaee, S., Ju, X., Judd, E. G., Kabana, S., Kagamaster, S., Kalinkin, D., Kang, K., Kapukchyan, D., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kikoła, D. P., Kim, C., Kinghorn, T. A., Kisel, I., Kisiel, A., Kochenda, L., Kosarzewski, L. K., Kraishan, A. F., Kramarik, L., Krauth, L., Kravtsov, P., Krueger, K., Kulathunga, N., Kumar, L., Elayavalli, R. Kunnawalkam, Kvapil, J., Kwasizur, J. H., Lacey, R., Landgraf, J. M., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Li, C., Li, W., Li, X., Li, Y., Liang, Y., Lidrych, J., Lin, T., Lipiec, A., Lisa, M. A., Liu, F., Liu, H., Liu, P., Liu, Y., Liu, Z., Ljubicic, T., Llope, W. J., Lomnitz, M., Longacre, R. S., Luo, S., Luo, X., Ma, G. L., Ma, L., Ma, R., Ma, Y. G., Magdy, N., Majka, R., Mallick, D., Margetis, S., Markert, C., Matis, H. S., Matonoha, O., Mazer, J. A., Meehan, K., Mei, J. C., Minaev, N. G., Mioduszewski, S., Mishra, D., Mohanty, B., Mondal, M. M., Mooney, I., Morozov, D. A., Nasim, Md., Negrete, J. D., Nelson, J. M., Nemes, D. B., Nie, M., Nigmatkulov, G., Niida, T., Nogach, L. V., Nonaka, T., Odyniec, G., Ogawa, A., Oh, K., Oh, S., Okorokov, V. A., Olvitt Jr., D., Page, B. S., Pak, R., Panebratsev, Y., Pawlik, B., Pei, H., Perkins, C., Pinter, R. L., Pluta, J., Porter, J., Posik, M., Pruthi, N. K., Przybycien, M., Putschke, J., Quintero, A., Radhakrishnan, S. K., Ramachandran, S., Ray, R. L., Reed, R., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ruan, L., Rusnak, J., Rusnakova, O., Sahoo, N. R., Sahu, P. K., Salur, S., Sandweiss, J., Schambach, J., Schmah, A. M., Schmidke, W. B., Schmitz, N., Schweid, B. R., Seck, F., Seger, J., Sergeeva, M., Seto, R., Seyboth, P., Shah, N., Shahaliev, E., Shanmuganathan, P. V., Shao, M., Shen, F., Shen, W. Q., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Siejka, S., Sikora, R., Simko, M., Singh, J, Singha, S., Smirnov, D., Smirnov, N., Solyst, W., Sorensen, P., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Stewart, D. J., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Sugiura, T., Sumbera, M., Summa, B., Sun, X. M., Sun, X., Sun, Y., Surrow, B., Svirida, D. N., Szymanski, P., Tang, A. H., Tang, Z., Taranenko, A., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Tlusty, D., Todoroki, T., Tokarev, M., Tomkiel, C. A., Trentalange, S., Tribble, R. E., Tribedy, P., Tripathy, S. K., Tsai, O. D., Tu, B., Ullrich, T., Underwood, D. G., Upsal, I., Van Buren, G., Vanek, J., Vasiliev, A. N., Vassiliev, I., Videbæk, F., Vokal, S., Voloshin, S. A., Vossen, A., Wang, F., Wang, G., Wang, P., Wang, Y., Webb, J. C., Wen, L., Westfall, G. D., Wieman, H., Wissink, S. W., Witt, R., Wu, Y., Xiao, Z. G., Xie, G., Xie, W., Xu, J., Xu, N., Xu, Q. H., Xu, Y. F., Xu, Z., Yang, C., Yang, Q., Yang, S., Yang, Y., Ye, Z., Yi, L., Yip, K., Yoo, I. -K., Yu, N., Zbroszczyk, H., Zha, W., Zhang, J., Zhang, L., Zhang, S., Zhang, X. P., Zhang, Y., Zhang, Z., Zhao, J., Zhong, C., Zhou, C., Zhu, X., Zhu, Z., and Zyzak, M.

Subjects
High Energy Physics - Experiment
Abstract

The transverse spin transfer from polarized protons to $\Lambda$ and $\bar{\Lambda}$ hyperons is expected to provide sensitivity to the transversity distribution of the nucleon and to the transversely polarized fragmentation functions. We report the first measurement of the transverse spin transfer to $\Lambda$ and $\bar{\Lambda}$ along the polarization direction of the fragmenting quark, $D_\mathrm{TT}$, in transversely polarized proton-proton collisions at $\sqrt{s}=200\,\mathrm{GeV}$ with the STAR detector at RHIC. The data correspond to an integrated luminosity of $18\,\mathrm{pb}^{-1}$ and cover the pseudorapidity range $\left|\eta\right| < 1.2$ and transverse momenta $p_{\mathrm{T}}$ up to $8\,\mathrm{GeV}/c$. The dependence on $p_\mathrm{T}$ and $\eta$ are presented. The $D_\mathrm{TT}$ results are found to be comparable with a model prediction, and are also consistent with zero within uncertainties., Comment: 8 pages, 4 figures, version to appear in Physical Review D

Published
2018
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46. Low-$p_T$ $e^{+}e^{-}$ pair production in Au$+$Au collisions at $\sqrt{s_{NN}}$ = 200 GeV and U$+$U collisions at $\sqrt{s_{NN}}$ = 193 GeV at STAR

Author

Adam, J., Adamczyk, L., Adams, J. R., Adkins, J. K., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Ajitanand, N. N., Alekseev, I., Anderson, D. M., Aoyama, R., Aparin, A., Arkhipkin, D., Aschenauer, E. C., Ashraf, M. U., Atetalla, F., Attri, A., Averichev, G. S., Bai, X., Bairathi, V., Barish, K., Bassill, A. J., Behera, A., Bellwied, R., Bhasin, A., Bhati, A. K., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Brandenburg, J. D., Brandin, A. V., Brown, D., Bryslawskyj, J., Bunzarov, I., Butterworth, J., Caines, H., Sánchez, M. Calderón de la Barca, Campbell, J. M., Cebra, D., Chakaberia, I., Chaloupka, P., Chang, F-H., Chang, Z., Chankova-Bunzarova, N., Chatterjee, A., Chattopadhyay, S., Chen, J. H., Chen, X., Cheng, J., Cherney, M., Christie, W., Contin, G., Crawford, H. J., Das, S., Dedovich, T. G., Deppner, I. M., Derevschikov, A. A., Didenko, L., Dilks, C., Dong, X., Drachenberg, J. L., Dunlop, J. C., Efimov, L. G., Elsey, N., Engelage, J., Eppley, G., Esha, R., Esumi, S., Evdokimov, O., Ewigleben, J., Eyser, O., Fatemi, R., Fazio, S., Federic, P., Federicova, P., Fedorisin, J., Filip, P., Finch, E., Fisyak, Y., Flores, C. E., Fulek, L., Gagliardi, C. A., Galatyuk, T., Geurts, F., Gibson, A., Grosnick, D., Gunarathne, D. S., Guo, Y., Gupta, A., Guryn, W., Hamad, A. I., Hamed, A., Harlenderova, A., Harris, J. W., He, L., Heppelmann, S., Herrmann, N., Hirsch, A., Holub, L., Horvat, S., Huang, X., Huang, B., Huang, S. L., Huang, H. Z., Huang, T., Humanic, T. J., Huo, P., Igo, G., Jacobs, W. W., Jentsch, A., Jia, J., Jiang, K., Jowzaee, S., Judd, E. G., Kabana, S., Kalinkin, D., Kang, K., Kapukchyan, D., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kikoła, D. P., Kim, C., Kinghorn, T. A., Kisel, I., Kisiel, A., Klein, S. R., Kochenda, L., Kosarzewski, L. K., Kraishan, A. F., Kramarik, L., Krauth, L., Kravtsov, P., Krueger, K., Kulathunga, N., Kumar, S., Kumar, L., Kvapil, J., Kwasizur, J. H., Lacey, R., Landgraf, J. M., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Li, X., Li, C., Li, W., Li, Y., Liang, Y., Lidrych, J., Lin, T., Lipiec, A., Lisa, M. A., Liu, F., Liu, P., Liu, H., Liu, Y., Ljubicic, T., Llope, W. J., Lomnitz, M., Longacre, R. S., Luo, X., Luo, S., Ma, G. L., Ma, Y. G., Ma, L., Ma, R., Magdy, N., Majka, R., Mallick, D., Margetis, S., Markert, C., Matis, H. S., Matonoha, O., Mayes, D., Mazer, J. A., Meehan, K., Mei, J. C., Minaev, N. G., Mioduszewski, S., Mishra, D., Mohanty, B., Mondal, M. M., Mooney, I., Morozov, D. A., Nasim, Md., Negrete, J. D., Nelson, J. M., Nemes, D. B., Nie, M., Nigmatkulov, G., Niida, T., Nogach, L. V., Nonaka, T., Nurushev, S. B., Odyniec, G., Ogawa, A., Oh, K., Oh, S., Okorokov, V. A., Olvitt Jr., D., Page, B. S., Pak, R., Panebratsev, Y., Pawlik, B., Pei, H., Perkins, C., Pluta, J., Porter, J., Posik, M., Pruthi, N. K., Przybycien, M., Putschke, J., Quintero, A., Radhakrishnan, S. K., Ramachandran, S., Ray, R. L., Reed, R., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ruan, L., Rusnak, J., Rusnakova, O., Sahoo, N. R., Sahu, P. K., Salur, S., Sandweiss, J., Schambach, J., Schmah, A. M., Schmidke, W. B., Schmitz, N., Schweid, B. R., Seck, F., Seger, J., Sergeeva, M., Seto, R., Seyboth, P., Shah, N., Shahaliev, E., Shanmuganathan, P. V., Shao, M., Shen, W. Q., Shen, F., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Siejka, S., Sikora, R., Simko, M., Singha, S., Smirnov, N., Smirnov, D., Solyst, W., Sorensen, P., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Stewart, D. J., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Sugiura, T., Sumbera, M., Summa, B., Sun, Y., Sun, X., Sun, X. M., Surrow, B., Svirida, D. N., Szymanski, P., Tang, Z., Tang, A. H., Taranenko, A., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Tlusty, D., Todoroki, T., Tokarev, M., Tomkiel, C. A., Trentalange, S., Tribble, R. E., Tribedy, P., Tripathy, S. K., Tsai, O. D., Tu, B., Ullrich, T., Underwood, D. G., Upsal, I., Van Buren, G., Vanek, J., Vasiliev, A. N., Vassiliev, I., Videbæk, F., Vokal, S., Voloshin, S. A., Vossen, A., Wang, G., Wang, Y., Wang, F., Webb, J. C., Wen, L., Westfall, G. D., Wieman, H., Wissink, S. W., Witt, R., Wu, Y., Xiao, Z. G., Xie, G., Xie, W., Xu, Q. H., Xu, Z., Xu, J., Xu, Y. F., Xu, N., Yang, S., Yang, C., Yang, Q., Yang, Y., Ye, Z., Yi, L., Yip, K., Yoo, I. -K., Yu, N., Zbroszczyk, H., Zha, W., Zhang, Z., Zhang, L., Zhang, Y., Zhang, X. P., Zhang, J., Zhang, S., Zhao, J., Zhong, C., Zhou, C., Zhou, L., Zhu, Z., Zhu, X., and Zyzak, M.

Subjects
High Energy Physics - Experiment, Nuclear Experiment
Abstract

We report first measurements of $e^{+}e^{-}$ pair production in the mass region 0.4 $

Published
2018
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47. Longitudinal Double-Spin Asymmetries for $\pi^{0}$s in the Forward Direction for 510 GeV Polarized $pp$ Collisions

Author

Adam, J., Adamczyk, L., Adams, J. R., Adkins, J. K., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Ajitanand, N. N., Alekseev, I., Anderson, D. M., Aoyama, R., Aparin, A., Arkhipkin, D., Aschenauer, E. C., Ashraf, M. U., Atetalla, F., Attri, A., Averichev, G. S., Bai, X., Bairathi, V., Barish, K., Bassill, A. J., Behera, A., Bellwied, R., Bhasin, A., Bhati, A. K., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Brandenburg, J. D., Brandin, A. V., Brown, D., Bryslawskyj, J., Bunzarov, I., Butterworth, J., Caines, H., Sánchez, M. Calderón de la Barca, Campbell, J. M., Cebra, D., Chakaberia, I., Chaloupka, P., Chang, F-H., Chang, Z., Chankova-Bunzarova, N., Chatterjee, A., Chattopadhyay, S., Chen, J. H., Chen, X., Cheng, J., Cherney, M., Christie, W., Contin, G., Crawford, H. J., Das, S., Dedovich, T. G., Deppner, I. M., Derevschikov, A. A., Didenko, L., Dilks, C., Dong, X., Drachenberg, J. L., Dunlop, J. C., Efimov, L. G., Elsey, N., Engelage, J., Eppley, G., Esha, R., Esumi, S., Evdokimov, O., Ewigleben, J., Eyser, O., Fatemi, R., Fazio, S., Federic, P., Federicova, P., Fedorisin, J., Filip, P., Finch, E., Fisyak, Y., Flores, C. E., Fulek, L., Gagliardi, C. A., Galatyuk, T., Geurts, F., Gibson, A., Grosnick, D., Gunarathne, D. S., Guo, Y., Gupta, A., Guryn, W., Hamad, A. I., Hamed, A., Harlenderova, A., Harris, J. W., He, L., Heppelmann, S., Herrmann, N., Hirsch, A., Holub, L., Horvat, S., Huang, X., Huang, B., Huang, S. L., Huang, H. Z., Huang, T., Humanic, T. J., Huo, P., Igo, G., Jacobs, W. W., Jentsch, A., Jia, J., Jiang, K., Jowzaee, S., Judd, E. G., Kabana, S., Kalinkin, D., Kang, K., Kapukchyan, D., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kikoła, D. P., Kim, C., Kinghorn, T. A., Kisel, I., Kisiel, A., Kochenda, L., Kosarzewski, L. K., Kraishan, A. F., Kramarik, L., Krauth, L., Kravtsov, P., Krueger, K., Kulathunga, N., Kumar, S., Kumar, L., Kvapil, J., Kwasizur, J. H., Lacey, R., Landgraf, J. M., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Li, X., Li, C., Li, W., Li, Y., Liang, Y., Lidrych, J., Lin, T., Lipiec, A., Lisa, M. A., Liu, F., Liu, P., Liu, H., Liu, Y., Ljubicic, T., Llope, W. J., Lomnitz, M., Longacre, R. S., Luo, X., Luo, S., Ma, G. L., Ma, Y. G., Ma, L., Ma, R., Magdy, N., Majka, R., Mallick, D., Margetis, S., Markert, C., Matis, H. S., Matonoha, O., Mayes, D., Mazer, J. A., Meehan, K., Mei, J. C., Minaev, N. G., Mioduszewski, S., Mishra, D., Mohanty, B., Mondal, M. M., Mooney, I., Morozov, D. A., Nasim, Md., Negrete, J. D., Nelson, J. M., Nemes, D. B., Nie, M., Nigmatkulov, G., Niida, T., Nogach, L. V., Nonaka, T., Nurushev, S. B., Odyniec, G., Ogawa, A., Oh, K., Oh, S., Okorokov, V. A., Olvitt Jr., D., Page, B. S., Pak, R., Panebratsev, Y., Pawlik, B., Pei, H., Perkins, C., Pluta, J., Porter, J., Posik, M., Pruthi, N. K., Przybycien, M., Putschke, J., Quintero, A., Radhakrishnan, S. K., Ramachandran, S., Ray, R. L., Reed, R., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ruan, L., Rusnak, J., Rusnakova, O., Sahoo, N. R., Sahu, P. K., Salur, S., Sandweiss, J., Schambach, J., Schmah, A. M., Schmidke, W. B., Schmitz, N., Schweid, B. R., Seck, F., Seger, J., Sergeeva, M., Seto, R., Seyboth, P., Shah, N., Shahaliev, E., Shanmuganathan, P. V., Shao, M., Shen, W. Q., Shen, F., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Siejka, S., Sikora, R., Simko, M., Singha, S., Smirnov, N., Smirnov, D., Solyst, W., Sorensen, P., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Stewart, D. J., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Sugiura, T., Sumbera, M., Summa, B., Sun, Y., Sun, X., Sun, X. M., Surrow, B., Svirida, D. N., Szymanski, P., Tang, Z., Tang, A. H., Taranenko, A., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Tlusty, D., Todoroki, T., Tokarev, M., Tomkiel, C. A., Trentalange, S., Tribble, R. E., Tribedy, P., Tripathy, S. K., Tsai, O. D., Tu, B., Ullrich, T., Underwood, D. G., Upsal, I., Van Buren, G., Vanek, J., Vasiliev, A. N., Vassiliev, I., Videbæk, F., Vokal, S., Voloshin, S. A., Vossen, A., Wang, G., Wang, Y., Wang, F., Webb, J. C., Wen, L., Westfall, G. D., Wieman, H., Wissink, S. W., Witt, R., Wu, Y., Xiao, Z. G., Xie, G., Xie, W., Xu, Q. H., Xu, Z., Xu, J., Xu, Y. F., Xu, N., Yang, S., Yang, C., Yang, Q., Yang, Y., Ye, Z., Yi, L., Yip, K., Yoo, I. -K., Yu, N., Zbroszczyk, H., Zha, W., Zhang, Z., Zhang, L., Zhang, Y., Zhang, X. P., Zhang, J., Zhang, S., Zhao, J., Zhong, C., Zhou, C., Zhou, L., Zhu, Z., Zhu, X., and Zyzak, M.

Subjects
High Energy Physics - Experiment, Nuclear Experiment
Abstract

The STAR Collaboration reports measurements of the longitudinal double-spin asymmetry, $A_{LL}$, for neutral pions produced at forward directions in polarized proton-proton collisions, at a center-of-mass energy of $510$ GeV. Results are given for transverse momenta in the range $2

Published
2018
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48. Longitudinal Double-Spin Asymmetries for Dijet Production at Intermediate Pseudorapidity in Polarized $pp$ Collisions at $\sqrt{s}$ = 200 GeV

Author

Adam, J., Adamczyk, L., Adams, J. R., Adkins, J. K., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Ajitanand, N. N., Alekseev, I., Anderson, D. M., Aoyama, R., Aparin, A., Arkhipkin, D., Aschenauer, E. C., Ashraf, M. U., Atetalla, F., Attri, A., Averichev, G. S., Bai, X., Bairathi, V., Barish, K., Bassill, A. J., Behera, A., Bellwied, R., Bhasin, A., Bhati, A. K., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Brandenburg, J. D., Brandin, A. V., Brown, D., Bryslawskyj, J., Bunzarov, I., Butterworth, J., Caines, H., Sánchez, M. Calderón de la Barca, Campbell, J. M., Cebra, D., Chakaberia, I., Chaloupka, P., Chang, F-H., Chang, Z., Chankova-Bunzarova, N., Chatterjee, A., Chattopadhyay, S., Chen, J. H., Chen, X., Cheng, J., Cherney, M., Christie, W., Contin, G., Crawford, H. J., Das, S., Dedovich, T. G., Deppner, I. M., Derevschikov, A. A., Didenko, L., Dilks, C., Dong, X., Drachenberg, J. L., Dunlop, J. C., Efimov, L. G., Elsey, N., Engelage, J., Eppley, G., Esha, R., Esumi, S., Evdokimov, O., Ewigleben, J., Eyser, O., Fatemi, R., Fazio, S., Federic, P., Federicova, P., Fedorisin, J., Filip, P., Finch, E., Fisyak, Y., Flores, C. E., Fulek, L., Gagliardi, C. A., Galatyuk, T., Geurts, F., Gibson, A., Grosnick, D., Gunarathne, D. S., Guo, Y., Gupta, A., Guryn, W., Hamad, A. I., Hamed, A., Harlenderova, A., Harris, J. W., He, L., Heppelmann, S., Herrmann, N., Hirsch, A., Holub, L., Horvat, S., Huang, X., Huang, B., Huang, S. L., Huang, H. Z., Huang, T., Humanic, T. J., Huo, P., Igo, G., Jacobs, W. W., Jentsch, A., Jia, J., Jiang, K., Jowzaee, S., Judd, E. G., Kabana, S., Kalinkin, D., Kang, K., Kapukchyan, D., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kikoła, D. P., Kim, C., Kinghorn, T. A., Kisel, I., Kisiel, A., Kochenda, L., Kosarzewski, L. K., Kraishan, A. F., Kramarik, L., Krauth, L., Kravtsov, P., Krueger, K., Kulathunga, N., Kumar, S., Kumar, L., Kvapil, J., Kwasizur, J. H., Lacey, R., Landgraf, J. M., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Li, X., Li, C., Li, W., Li, Y., Liang, Y., Lidrych, J., Lin, T., Lipiec, A., Lisa, M. A., Liu, F., Liu, P., Liu, H., Liu, Y., Ljubicic, T., Llope, W. J., Lomnitz, M., Longacre, R. S., Luo, X., Luo, S., Ma, G. L., Ma, Y. G., Ma, L., Ma, R., Magdy, N., Majka, R., Mallick, D., Margetis, S., Markert, C., Matis, H. S., Matonoha, O., Mayes, D., Mazer, J. A., Meehan, K., Mei, J. C., Minaev, N. G., Mioduszewski, S., Mishra, D., Mohanty, B., Mondal, M. M., Mooney, I., Morozov, D. A., Nasim, Md., Negrete, J. D., Nelson, J. M., Nemes, D. B., Nie, M., Nigmatkulov, G., Niida, T., Nogach, L. V., Nonaka, T., Nurushev, S. B., Odyniec, G., Ogawa, A., Oh, K., Oh, S., Okorokov, V. A., Olvitt Jr., D., Page, B. S., Pak, R., Panebratsev, Y., Pawlik, B., Pei, H., Perkins, C., Pluta, J., Porter, J., Posik, M., Pruthi, N. K., Przybycien, M., Putschke, J., Quintero, A., Radhakrishnan, S. K., Ramachandran, S., Ray, R. L., Reed, R., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ruan, L., Rusnak, J., Rusnakova, O., Sahoo, N. R., Sahu, P. K., Salur, S., Sandweiss, J., Schambach, J., Schmah, A. M., Schmidke, W. B., Schmitz, N., Schweid, B. R., Seck, F., Seger, J., Sergeeva, M., Seto, R., Seyboth, P., Shah, N., Shahaliev, E., Shanmuganathan, P. V., Shao, M., Shen, W. Q., Shen, F., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Siejka, S., Sikora, R., Simko, M., Singha, S., Smirnov, N., Smirnov, D., Solyst, W., Sorensen, P., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Stewart, D. J., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Sugiura, T., Sumbera, M., Summa, B., Sun, Y., Sun, X., Sun, X. M., Surrow, B., Svirida, D. N., Szymanski, P., Tang, Z., Tang, A. H., Taranenko, A., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Tlusty, D., Todoroki, T., Tokarev, M., Tomkiel, C. A., Trentalange, S., Tribble, R. E., Tribedy, P., Tripathy, S. K., Tsai, O. D., Tu, B., Ullrich, T., Underwood, D. G., Upsal, I., Van Buren, G., Vanek, J., Vasiliev, A. N., Vassiliev, I., Videbæk, F., Vokal, S., Voloshin, S. A., Vossen, A., Wang, G., Wang, Y., Wang, F., Webb, J. C., Wen, L., Westfall, G. D., Wieman, H., Wissink, S. W., Witt, R., Wu, Y., Xiao, Z. G., Xie, G., Xie, W., Xu, Q. H., Xu, Z., Xu, J., Xu, Y. F., Xu, N., Yang, S., Yang, C., Yang, Q., Yang, Y., Ye, Z., Yi, L., Yip, K., Yoo, I. -K., Yu, N., Zbroszczyk, H., Zha, W., Zhang, Z., Zhang, L., Zhang, Y., Zhang, X. P., Zhang, J., Zhang, S., Zhao, J., Zhong, C., Zhou, C., Zhou, L., Zhu, Z., Zhu, X., and Zyzak, M.

Subjects
High Energy Physics - Experiment, Nuclear Experiment
Abstract

We present the first measurements of the longitudinal double-spin asymmetry $A_{LL}$ for dijets with at least one jet reconstructed within the pseudorapidity range $0.8 < \eta < 1.8$. The dijets were measured in polarized $pp$ collisions at a center-of-mass energy $\sqrt{s}$ = 200 GeV. Values for $A_{LL}$ are determined for several distinct event topologies, defined by the jet pseudorapidities, and span a range of parton momentum fraction $x$ down to $x \sim$ 0.01. The measured asymmetries are found to be consistent with the predictions of global analyses that incorporate the results of previous RHIC measurements. They will provide new constraints on $\Delta g(x)$ in this poorly constrained region when included in future global analyses.

Published
2018
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49. Global polarization of $\Lambda$ hyperons in Au+Au collisions at $\sqrt{s_{_{NN}}}$ = 200 GeV

Author

Adam, J., Adamczyk, L., Adams, J. R., Adkins, J. K., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Ajitanand, N. N., Alekseev, I., Anderson, D. M., Aoyama, R., Aparin, A., Arkhipkin, D., Aschenauer, E. C., Ashraf, M. U., Atetalla, F., Attri, A., Averichev, G. S., Bai, X., Bairathi, V., Barish, K., Bassill, A. J., Behera, A., Bellwied, R., Bhasin, A., Bhati, A. K., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Brandenburg, J. D., Brandin, A. V., Brown, D., Bryslawskyj, J., Bunzarov, I., Butterworth, J., Caines, H., Calderón~de~la~Barca~Sánchez, M., Campbell, J. M., Cebra, D., Chakaberia, I., Chaloupka, P., Chang, F-H., Chang, Z., Chankova-Bunzarova, N., Chatterjee, A., Chattopadhyay, S., Chen, J. H., Chen, X., Cheng, J., Cherney, M., Christie, W., Contin, G., Crawford, H. J., Das, S., Dedovich, T. G., Deppner, I. M., Derevschikov, A. A., Didenko, L., Dilks, C., Dong, X., Drachenberg, J. L., Dunlop, J. C., Efimov, L. G., Elsey, N., Engelage, J., Eppley, G., Esha, R., Esumi, S., Evdokimov, O., Ewigleben, J., Eyser, O., Fatemi, R., Fazio, S., Federic, P., Federicova, P., Fedorisin, J., Filip, P., Finch, E., Fisyak, Y., Flores, C. E., Fulek, L., Gagliardi, C. A., Galatyuk, T., Geurts, F., Gibson, A., Grosnick, D., Gunarathne, D. S., Guo, Y., Gupta, A., Guryn, W., Hamad, A. I., Hamed, A., Harlenderova, A., Harris, J. W., He, L., Heppelmann, S., Herrmann, N., Hirsch, A., Holub, L., Horvat, S., Huang, X., Huang, B., Huang, S. L., Huang, H. Z., Huang, T., Humanic, T. J., Huo, P., Igo, G., Jacobs, W. W., Jentsch, A., Jia, J., Jiang, K., Jowzaee, S., Judd, E. G., Kabana, S., Kalinkin, D., Kang, K., Kapukchyan, D., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kikoła, D. P., Kim, C., Kinghorn, T. A., Kisel, I., Kisiel, A., Kochenda, L., Kosarzewski, L. K., Kraishan, A. F., Kramarik, L., Krauth, L., Kravtsov, P., Krueger, K., Kulathunga, N., Kumar, S., Kumar, L., Kvapil, J., Kwasizur, J. H., Lacey, R., Landgraf, J. M., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Li, X., Li, C., Li, W., Li, Y., Liang, Y., Lidrych, J., Lin, T., Lipiec, A., Lisa, M. A., Liu, F., Liu, P., Liu, H., Liu, Y., Ljubicic, T., Llope, W. J., Lomnitz, M., Longacre, R. S., Luo, X., Luo, S., Ma, G. L., Ma, Y. G., Ma, L., Ma, R., Magdy, N., Majka, R., Mallick, D., Margetis, S., Markert, C., Matis, H. S., Matonoha, O., Mayes, D., Mazer, J. A., Meehan, K., Mei, J. C., Minaev, N. G., Mioduszewski, S., Mishra, D., Mohanty, B., Mondal, M. M., Mooney, I., Morozov, D. A., Nasim, Md., Negrete, J. D., Nelson, J. M., Nemes, D. B., Nie, M., Nigmatkulov, G., Niida, T., Nogach, L. V., Nonaka, T., Nurushev, S. B., Odyniec, G., Ogawa, A., Oh, K., Oh, S., Okorokov, V. A., Olvitt Jr., D., Page, B. S., Pak, R., Panebratsev, Y., Pawlik, B., Pei, H., Perkins, C., Pluta, J., Porter, J., Posik, M., Pruthi, N. K., Przybycien, M., Putschke, J., Quintero, A., Radhakrishnan, S. K., Ramachandran, S., Ray, R. L., Reed, R., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ruan, L., Rusnak, J., Rusnakova, O., Sahoo, N. R., Sahu, P. K., Salur, S., Sandweiss, J., Schambach, J., Schmah, A. M., Schmidke, W. B., Schmitz, N., Schweid, B. R., Seck, F., Seger, J., Sergeeva, M., Seto, R., Seyboth, P., Shah, N., Shahaliev, E., Shanmuganathan, P. V., Shao, M., Shen, W. Q., Shen, F., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Siejka, S., Sikora, R., Simko, M., Singha, S., Smirnov, N., Smirnov, D., Solyst, W., Sorensen, P., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Stewart, D. J., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Sugiura, T., Sumbera, M., Summa, B., Sun, Y., Sun, X., Sun, X. M., Surrow, B., Svirida, D. N., Szymanski, P., Tang, Z., Tang, A. H., Taranenko, A., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Tlusty, D., Todoroki, T., Tokarev, M., Tomkiel, C. A., Trentalange, S., Tribble, R. E., Tribedy, P., Tripathy, S. K., Tsai, O. D., Tu, B., Ullrich, T., Underwood, D. G., Upsal, I., Van Buren, G., Vanek, J., Vasiliev, A. N., Vassiliev, I., Videbæk, F., Vokal, S., Voloshin, S. A., Vossen, A., Wang, G., Wang, Y., Wang, F., Webb, J. C., Wen, L., Westfall, G. D., Wieman, H., Wissink, S. W., Witt, R., Wu, Y., Xiao, Z. G., Xie, G., Xie, W., Xu, Q. H., Xu, Z., Xu, J., Xu, Y. F., Xu, N., Yang, S., Yang, C., Yang, Q., Yang, Y., Ye, Z., Yi, L., Yip, K., Yoo, I. -K., Yu, N., Zbroszczyk, H., Zha, W., Zhang, Z., Zhang, L., Zhang, Y., Zhang, X. P., Zhang, J., Zhang, S., Zhao, J., Zhong, C., Zhou, C., Zhou, L., Zhu, Z., Zhu, X., and Zyzak, M.

Subjects
Nuclear Experiment
Abstract

Global polarization of $\Lambda$ hyperons has been measured to be of the order of a few tenths of a percent in Au+Au collisions at $\sqrt{s_{_{NN}}}$ = 200 GeV, with no significant difference between $\Lambda$ and $\bar{\Lambda}$. These new results reveal the collision energy dependence of the global polarization together with the results previously observed at $\sqrt{s_{_{NN}}}$ = 7.7 -- 62.4 GeV and indicate noticeable vorticity of the medium created in non-central heavy-ion collisions at the highest RHIC collision energy. The signal is in rough quantitative agreement with the theoretical predictions from a hydrodynamic model and from the AMPT (A Multi-Phase Transport) model. The polarization is larger in more peripheral collisions, and depends weakly on the hyperon's transverse momentum and pseudorapidity $\eta^H$ within $|\eta^H|<1$. An indication of the polarization dependence on the event-by-event charge asymmetry is observed at the $2\sigma$ level, suggesting a possible contribution to the polarization from the axial current induced by the initial magnetic field., Comment: 11 pages, 8 figures, Accepted for publication in Phys. Rev. C

Published
2018
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50. $J/\psi$ production cross section and its dependence on charged-particle multiplicity in $p+p$ collisions at $\sqrt{s}$ = 200 GeV

Author

STAR Collaboration, Adam, J., Adamczyk, L., Adams, J. R., Adkins, J. K., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Ajitanand, N. N., Alekseev, I., Anderson, D. M., Aoyama, R., Aparin, A., Arkhipkin, D., Aschenauer, E. C., Ashraf, M. U., Atetalla, F., Attri, A., Averichev, G. S., Bai, X., Bairathi, V., Barish, K., Bassill, A. J., Behera, A., Bellwied, R., Bhasin, A., Bhati, A. K., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Brandenburg, J. D., Brandin, A. V., Brown, D., Bryslawskyj, J., Bunzarov, I., Butterworth, J., Caines, H., Sanchez, M. Calderon de la Barca, Campbell, J. M., Cebra, D., Chakaberia, I., Chaloupka, P., Chang, F-H., Chang, Z., Chankova-Bunzarova, N., Chatterjee, A., Chattopadhyay, S., Chen, J. H., Chen, X., Cheng, J., Cherney, M., Christie, W., Contin, G., Crawford, H. J., Das, S., Dedovich, T. G., Deppner, I. M., Derevschikov, A. A., Didenko, L., Dilks, C., Dong, X., Drachenberg, J. L., Dunlop, J. C., Efimov, L. G., Elsey, N., Engelage, J., Eppley, G., Esha, R., Esumi, S., Evdokimov, O., Ewigleben, J., Eyser, O., Fatemi, R., Fazio, S., Federic, P., Federicova, P., Fedorisin, J., Filip, P., Finch, E., Fisyak, Y., Flores, C. E., Fulek, L., Gagliardi, C. A., Galatyuk, T., Geurts, F., Gibson, A., Grosnick, D., Gunarathne, D. S., Guo, Y., Gupta, A., Guryn, W., Hamad, A. I., Hamed, A., Harlenderova, A., Harris, J. W., He, L., Heppelmann, S., Herrmann, N., Hirsch, A., Holub, L., Horvat, S., Huang, X., Huang, B., Huang, S. L., Huang, H. Z., Huang, T., Humanic, T. J., Huo, P., Igo, G., Jacobs, W. W., Jentsch, A., Jia, J., Jiang, K., Jowzaee, S., Judd, E. G., Kabana, S., Kalinkin, D., Kang, K., Kapukchyan, D., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kikoła, D. P., Kim, C., Kinghorn, T. A., Kisel, I., Kisiel, A., Kochenda, L., Kosarzewski, L. K., Kraishan, A. F., Kramarik, L., Krauth, L., Kravtsov, P., Krueger, K., Kulathunga, N., Kumar, S., Kumar, L., Kvapil, J., Kwasizur, J. H., Lacey, R., Landgraf, J. M., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Li, X., Li, C., Li, W., Li, Y., Liang, Y., Lidrych, J., Lin, T., Lipiec, A., Lisa, M. A., Liu, F., Liu, P., Liu, H., Liu, Y., Ljubicic, T., Llope, W. J., Lomnitz, M., Longacre, R. S., Luo, X., Luo, S., Ma, G. L., Ma, Y. G., Ma, L., Ma, R., Magdy, N., Majka, R., Mallick, D., Margetis, S., Markert, C., Matis, H. S., Matonoha, O., Mayes, D., Mazer, J. A., Meehan, K., Mei, J. C., Minaev, N. G., Mioduszewski, S., Mishra, D., Mohanty, B., Mondal, M. M., Mooney, I., Morozov, D. A., Nasim, Md., Negrete, J. D., Nelson, J. M., Nemes, D. B., Nie, M., Nigmatkulov, G., Niida, T., Nogach, L. V., Nonaka, T., Nurushev, S. B., Odyniec, G., Ogawa, A., Oh, K., Oh, S., Okorokov, V. A., Olvitt Jr., D., Page, B. S., Pak, R., Panebratsev, Y., Pawlik, B., Pei, H., Perkins, C., Pluta, J., Porter, J., Posik, M., Pruthi, N. K., Przybycien, M., Putschke, J., Quintero, A., Radhakrishnan, S. K., Ramachandran, S., Ray, R. L., Reed, R., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ruan, L., Rusnak, J., Rusnakova, O., Sahoo, N. R., Sahu, P. K., Salur, S., Sandweiss, J., Schambach, J., Schmah, A. M., Schmidke, W. B., Schmitz, N., Schweid, B. R., Seck, F., Seger, J., Sergeeva, M., Seto, R., Seyboth, P., Shah, N., Shahaliev, E., Shanmuganathan, P. V., Shao, M., Shen, W. Q., Shen, F., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Siejka, S., Sikora, R., Simko, M., Singha, S., Smirnov, N., Smirnov, D., Solyst, W., Sorensen, P., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Stewart, D. J., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Sugiura, T., Sumbera, M., Summa, B., Sun, Y., Sun, X., Sun, X. M., Surrow, B., Svirida, D. N., Szymanski, P., Tang, Z., Tang, A. H., Taranenko, A., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Tlusty, D., Todoroki, T., Tokarev, M., Tomkiel, C. A., Trentalange, S., Tribble, R. E., Tribedy, P., Tripathy, S. K., Tsai, O. D., Tu, B., Ullrich, T., Underwood, D. G., Upsal, I., Van Buren, G., Vanek, J., Vasiliev, A. N., Vassiliev, I., Videbæk, F., Vokal, S., Voloshin, S. A., Vossen, A., Wang, G., Wang, Y., Wang, F., Webb, J. C., Wen, L., Westfall, G. D., Wieman, H., Wissink, S. W., Witt, R., Wu, Y., Xiao, Z. G., Xie, G., Xie, W., Xu, Q. H., Xu, Z., Xu, J., Xu, Y. F., Xu, N., Yang, S., Yang, C., Yang, Q., Yang, Y., Ye, Z., Yi, L., Yip, K., Yoo, I. -K., Yu, N., Zbroszczyk, H., Zha, W., Zhang, Z., Zhang, L., Zhang, Y., Zhang, X. P., Zhang, J., Zhang, S., Zhao, J., Zhong, C., Zhou, C., Zhou, L., Zhu, Z., Zhu, X., and Zyzak, M.

Subjects
High Energy Physics - Experiment, Nuclear Experiment
Abstract

We present a measurement of inclusive $J/\psi$ production at mid-rapidity ($|y|<1$) in $p+p$ collisions at a center-of-mass energy of $\sqrt{s}$ = 200 GeV with the STAR experiment at the Relativistic Heavy Ion Collider (RHIC). The differential production cross section for $J/\psi$ as a function of transverse momentum ($p_T$) for $0

Published
2018

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