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1. Measurements of dihadron correlations relative to the event plane in Au+Au collisions at GeV

Author

Agakishiev, H, Aggarwal, MM, Ahammed, Z, Alakhverdyants, AV, Alekseev, I, Alford, J, Anderson, BD, Anson, CD, Arkhipkin, D, Averichev, GS, Balewski, J, Beavis, DR, Behera, NK, Bellwied, R, Betancourt, MJ, Betts, RR, Bhasin, A, Bhati, AK, Bichsel, H, Bielcik, J, Bielcikova, J, Biritz, B, Bland, LC, Borowski, W, Bouchet, J, Braidot, E, Brandin, AV, Bridgeman, A, Brovko, SG, Bruna, E, Bueltmann, S, Bunzarov, I, Burton, TP, Cai, XZ, Caines, H, de la Barca Sánchez, M Calderón, Cebra, D, Cendejas, R, Cervantes, MC, Chajecki, Z, Chaloupka, P, Chattopadhyay, S, Chen, HF, Chen, JH, Chen, JY, Chen, L, Cheng, J, Cherney, M, Chikanian, A, Choi, KE, Christie, W, Chung, P, Codrington, MJM, Corliss, R, Cramer, JG, Crawford, HJ, Dash, S, Leyva, A Davila, De Silva, LC, Debbe, RR, Dedovich, TG, Derevschikov, AA, de Souza, R Derradi, Didenko, L, Djawotho, P, Dogra, SM, Dong, X, Drachenberg, JL, Draper, JE, Dunlop, JC, Efimov, LG, Elnimr, M, Engelage, J, Eppley, G, Estienne, M, Eun, L, Evdokimov, O, Fatemi, R, Fedorisin, J, Feng, A, Fersch, RG, Filip, P, Finch, E, Fine, V, Fisyak, Y, Gagliardi, CA, Gangadharan, DR, Geromitsos, A, Geurts, F, Ghosh, P, Gorbunov, YN, Gordon, A, Grebenyuk, O, Grosnick, D, Guertin, SM, Gupta, A, Guryn, W, Haag, B, Hajkova, O, and Hamed, A

Subjects
Nuclear and Plasma Physics, Particle and High Energy Physics, Physical Sciences, relativistic heavy ion collisions, dihadron correlations, jet-medium interactions, anisotropic flow background, event plane, nucl-ex, nucl-th, NSD-Relativistic Nuclear Collisions, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Nuclear & Particles Physics, Atomic, molecular and optical physics, Particle and high energy physics
Abstract

Dihadron azimuthal correlations containing a high transverse momentum (pT) trigger particle are sensitive to the properties of the nuclear medium created at RHIC through the strong interactions occurring between the traversing parton and the medium, i.e. jet-quenching. Previous measurements revealed a strong modification to dihadron azimuthal correlations in Au+Au collisions with respect to p+p and d+Au collisions. The modification increases with the collision centrality, suggesting a path-length or energy density dependence to the jet-quenching effect. This paper reports STAR measurements of dihadron azimuthal correlations in mid-central (20%-60%) Au+Au collisions at GeV as a function of the trigger particle's azimuthal angle relative to the event plane, . The azimuthal correlation is studied as a function of both the trigger and associated particle . The subtractions of the combinatorial background and anisotropic flow, assuming Zero Yield At Minimum (ZYAM), are described. The correlation results are first discussed with subtraction of the even harmonic (elliptic and quadrangular) flow backgrounds. The away-side correlation is strongly modified, and the modification varies with , with a double-peak structure for out-of-plane trigger particles. The near-side ridge (long range pseudo-rapidity correlation) appears to drop with increasing while the jet-like component remains approximately constant. The correlation functions are further studied with the subtraction of odd harmonic triangular flow background arising from fluctuations. It is found that the triangular flow, while responsible for the majority of the amplitudes, is not sufficient to explain the -dependence of the ridge or the away-side double-peak structure. The dropping ridge with could be attributed to a -dependent elliptic anisotropy; however, the physics mechanism of the ridge remains an open question. Even with a -dependent elliptic flow, the away-side correlation structure is robust. These results, with extensive systematic studies of the dihadron correlations as a function of , trigger and associated particle , and the pseudo-rapidity range , should provide stringent inputs to help understand the underlying physics mechanisms of jet-medium interactions in high energy nuclear collisions.

Published
2021

2. Measurements of dihadron correlations relative to the event plane in Au+Au collisions at √sNN= 200 GeV

Author

Agakishiev, H, Aggarwal, MM, Ahammed, Z, Alakhverdyants, AV, Alekseev, I, Alford, J, Anderson, BD, Anson, CD, Arkhipkin, D, Averichev, GS, Balewski, J, Beavis, DR, Behera, NK, Bellwied, R, Betancourt, MJ, Betts, RR, Bhasin, A, Bhati, AK, Bichsel, H, Bielcik, J, Bielcikova, J, Biritz, B, Bland, LC, Borowski, W, Bouchet, J, Braidot, E, Brandin, AV, Bridgeman, A, Brovko, SG, Bruna, E, Bueltmann, S, Bunzarov, I, Burton, TP, Cai, XZ, Caines, H, Calderón De La Barca Sánchez, M, Cebra, D, Cendejas, R, Cervantes, MC, Chajecki, Z, Chaloupka, P, Chattopadhyay, S, Chen, HF, Chen, JH, Chen, JY, Chen, L, Cheng, J, Cherney, M, Chikanian, A, Choi, KE, Christie, W, Chung, P, Codrington, MJM, Corliss, R, Cramer, JG, Crawford, HJ, Dash, S, Davila Leyva, A, De Silva, LC, Debbe, RR, Dedovich, TG, Derevschikov, AA, Derradi De Souza, R, Didenko, L, Djawotho, P, Dogra, SM, Dong, X, Drachenberg, JL, Draper, JE, Dunlop, JC, Efimov, LG, Elnimr, M, Engelage, J, Eppley, G, Estienne, M, Eun, L, Evdokimov, O, Fatemi, R, Fedorisin, J, Feng, A, Fersch, RG, Filip, P, Finch, E, Fine, V, Fisyak, Y, Gagliardi, CA, Gangadharan, DR, Geromitsos, A, Geurts, F, Ghosh, P, Gorbunov, YN, Gordon, A, Grebenyuk, O, Grosnick, D, Guertin, SM, Gupta, A, Guryn, W, Haag, B, Hajkova, O, and Hamed, A

Subjects
relativistic heavy ion collisions, dihadron correlations, jet-medium interactions, anisotropic flow background, event plane, nucl-ex, nucl-th, Nuclear & Particles Physics, Atomic, Molecular, Nuclear, Particle and Plasma Physics
Abstract

Dihadron azimuthal correlations containing a high transverse momentum (pT) trigger particle are sensitive to the properties of the nuclear medium created at RHIC through the strong interactions occurring between the traversing parton and the medium, i.e. jet-quenching. Previous measurements revealed a strong modification to dihadron azimuthal correlations in Au+Au collisions with respect to p+p and d+Au collisions. The modification increases with the collision centrality, suggesting a path-length or energy density dependence to the jet-quenching effect. This paper reports STAR measurements of dihadron azimuthal correlations in mid-central (20%-60%) Au+Au collisions at GeV as a function of the trigger particle's azimuthal angle relative to the event plane, . The azimuthal correlation is studied as a function of both the trigger and associated particle . The subtractions of the combinatorial background and anisotropic flow, assuming Zero Yield At Minimum (ZYAM), are described. The correlation results are first discussed with subtraction of the even harmonic (elliptic and quadrangular) flow backgrounds. The away-side correlation is strongly modified, and the modification varies with , with a double-peak structure for out-of-plane trigger particles. The near-side ridge (long range pseudo-rapidity correlation) appears to drop with increasing while the jet-like component remains approximately constant. The correlation functions are further studied with the subtraction of odd harmonic triangular flow background arising from fluctuations. It is found that the triangular flow, while responsible for the majority of the amplitudes, is not sufficient to explain the -dependence of the ridge or the away-side double-peak structure. The dropping ridge with could be attributed to a -dependent elliptic anisotropy; however, the physics mechanism of the ridge remains an open question. Even with a -dependent elliptic flow, the away-side correlation structure is robust. These results, with extensive systematic studies of the dihadron correlations as a function of , trigger and associated particle , and the pseudo-rapidity range , should provide stringent inputs to help understand the underlying physics mechanisms of jet-medium interactions in high energy nuclear collisions.

Published
2021

3. Isolation of Flow and Nonflow Correlations by Two- and Four-Particle Cumulant Measurements of Azimuthal Harmonics in $\sqrt{s_{_{\rm NN}}} =$ 200 GeV Au+Au Collisions

Author

Abdelwahab, N. M., Adamczyk, L., Adkins, J. K., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alekseev, I., Alford, J., Anson, C. D., Aparin, A., Arkhipkin, D., Aschenauer, E. C., Averichev, G. S., Banerjee, A., Beavis, D. R., Bellwied, R., Bhasin, A., Bhati, A. K., Bhattarai, P., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Borowski, W., Bouchet, J., Brandin, A. V., Brovko, S. G., Bültmann, S., Bunzarov, I., Burton, T. P., Butterworth, J., Caines, H., Sánchez, M. Calderóndela Barca, Campbell, J. M., Cebra, D., Cendejas, R., Cervantes, M. C., Chaloupka, P., Chang, Z., Chattopadhyay, S., Chen, H. F., Chen, J. H., Chen, L., Cheng, J., Cherney, M., Chikanian, A., Christie, W., Chwastowski, J., Codrington, M. J. M., Contin, G., Cramer, J. G., Crawford, H. J., Cui, X., Das, S., Leyva, A. Davila, De Silva, L. C., Debbe, R. R., Dedovich, T. G., Deng, J., Derevschikov, A. A., de Souza, R. Derradi, di Ruzza, B., Didenko, L., Dilks, C., Ding, F., Djawotho, P., Dong, X., Drachenberg, J. L., Draper, J. E., Du, C. M., Dunkelberger, L. E., Dunlop, J. C., Efimov, L. G., Engelage, J., Engle, K. S., Eppley, G., Eun, L., Evdokimov, O., Eyser, O., Fatemi, R., Fazio, S., Fedorisin, J., Filip, P., Fisyak, Y., Flores, C. E., Gagliardi, C. A., Gangadharan, D. R., Garand, D., Geurts, F., Gibson, A., Girard, M., Gliske, S., Greiner, L., Grosnick, D., Gunarathne, D. S., Guo, Y., Gupta, A., Gupta, S., Guryn, W., Haag, B., Hamed, A., Han, L-X., Haque, R., Harris, J. W., Heppelmann, S., Hirsch, A., Hoffmann, G. W., Hofman, D. J., Horvat, S., Huang, B., Huang, H. Z., Huang, X., Huck, P., Humanic, T. J., Igo, G., Jacobs, W. W., Jang, H., Judd, E. G., Kabana, S., Kalinkin, D., Kang, K., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kesich, A., Khan, Z. H., Kikola, D. P., Kisel, I., Kisiel, A., Koetke, D. D., Kollegger, T., Konzer, J., Koralt, I., Kosarzewski, L. K., Kotchenda, L., Kraishan, A. F., Kravtsov, P., Krueger, K., Kulakov, I., Kumar, L., Kycia, R. A., Lamont, M. A. C., Landgraf, J. M., Landry, K. D., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Li, C., Li, W., Li, X., Li, Y., Li, Z. M., Lisa, M. A., Liu, F., Ljubicic, T., Llope, W. J., Lomnitz, M., Longacre, R. S., Luo, X., Ma, G. L., Ma, Y. G., Mahapatra, D. P., Majka, R., Margetis, S., Markert, C., Masui, H., Matis, H. S., McDonald, D., McShane, T. S., Minaev, N. G., Mioduszewski, S., Mohanty, B., Mondal, M. M., Morozov, D. A., Mustafa, M. K., Nandi, B. K., Nasim, Md., Nayak, T. K., Nelson, J. M., Nigmatkulov, G., Nogach, L. V., Noh, S. Y., Novak, J., Nurushev, S. B., Odyniec, G., Ogawa, A., Oh, K., Ohlson, A., Okorokov, V., Oldag, E. W., Olvitt Jr., D. L., Page, B. S., Pan, Y. X., Pandit, Y., Panebratsev, Y., Pawlak, T., Pawlik, B., Pei, H., Perkins, C., Pile, P., Planinic, M., Pluta, J., Poljak, N., Poniatowska, K., Porter, J., Poskanzer, A. M., Pruthi, N. K., Przybycien, M., Putschke, J., Qiu, H., Quintero, A., Ramachandran, S., Raniwala, R., Raniwala, S., Ray, R. L., Riley, C. K., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ross, J. F., Roy, A., Ruan, L., Rusnak, J., Rusnakova, O., Sahoo, N. R., Sahu, P. K., Sakrejda, I., Salur, S., Sandacz, A., Sandweiss, J., Sangaline, E., Sarkar, A., Schambach, J., Scharenberg, R. P., Schmah, A. M., Schmidke, W. B., Schmitz, N., Seger, J., Seyboth, P., Shah, N., Shahaliev, E., Shanmuganathan, P. V., Shao, M., Sharma, B., Shen, W. Q., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Simko, M., Skoby, M. J., Smirnov, D., Smirnov, N., Solanki, D., Sorensen, P., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Stevens, J. R., Stock, R., Strikhanov, M., Stringfellow, B., Sumbera, M., Sun, X., Sun, X. M., Sun, Y., Sun, Z., Surrow, B., Svirida, D. N., Symons, T. J. M., Szelezniak, M. A., Takahashi, J., Tang, A. H., Tang, Z., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Tlusty, D., Tokarev, M., Trentalange, S., Tribble, R. E., Tribedy, P., Trzeciak, B. A., Tsai, O. D., Turnau, J., Ullrich, T., Underwood, D. G., Van Buren, G., van Nieuwenhuizen, G., Vandenbroucke, M., Vanfossen, Jr., J. A., Varma, R., Vasconcelos, G. M. S., Vasiliev, A. N., Vertesi, R., Videbæk, F., Viyogi, Y. P., Vokal, S., Vossen, A., Wada, M., Wang, F., Wang, G., Wang, H., Wang, J. S., Wang, X. L., Wang, Y., Webb, G., Webb, J. C., Westfall, G. D., Wieman, H., Wissink, S. W., Wu, Y. F., Xiao, Z., Xie, W., Xin, K., Xu, H., Xu, J., Xu, N., Xu, Q. H., Xu, Y., Xu, Z., Yan, W., Yang, C., Yang, Y., Ye, Z., Yepes, P., Yi, L., Yip, K., Yoo, I-K., Yu, N., Zbroszczyk, H., Zha, W., Zhang, J. B., Zhang, J. L., Zhang, S., Zhang, X. P., Zhang, Y., Zhang, Z. P., Zhao, F., Zhao, J., Zhong, C., Zhu, X., Zhu, Y. H., Zoulkarneeva, Y., and Zyzak, M.

Subjects
Nuclear Experiment
Abstract

A data-driven method was applied to measurements of Au+Au collisions at $\sqrt{s_{_{\rm NN}}} =$ 200 GeV made with the STAR detector at RHIC to isolate pseudorapidity distance $\Delta\eta$-dependent and $\Delta\eta$-independent correlations by using two- and four-particle azimuthal cumulant measurements. We identified a component of the correlation that is $\Delta\eta$-independent, which is likely dominated by anisotropic flow and flow fluctuations. It was also found to be independent of $\eta$ within the measured range of pseudorapidity $|\eta|<1$. The relative flow fluctuation was found to be $34\% \pm 2\% (stat.) \pm 3\% (sys.)$ for particles of transverse momentum $p_{T}$ less than $2$ GeV/$c$. The $\Delta\eta$-dependent part may be attributed to nonflow correlations, and is found to be $5\% \pm 2\% (sys.)$ relative to the flow of the measured second harmonic cumulant at $|\Delta\eta| > 0.7$.

Published
2014
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4. Charged-to-neutral correlation at forward rapidity in Au+Au collisions at $\sqrt{s_{NN}}$=200 GeV

Author

STAR Collaboration, Abdelwahab, N. M., Adamczyk, L., Adkins, J. K., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alekseev, I., Alford, J., Anson, C. D., Aparin, A., Arkhipkin, D., Aschenauer, E. C., Averichev, G. S., Banerjee, A., Beavis, D. R., Bellwied, R., Bhasin, A., Bhati, A. K., Bhattarai, P., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Borowski, W., Bouchet, J., Brandin, A. V., Brovko, S. G., Bültmann, S., Bunzarov, I., Burton, T. P., Butterworth, J., Caines, H., Sánchez, M. Calderón de la Barca, Campbell, J. M., Cebra, D., Cendejas, R., Cervantes, M. C., Chaloupka, P., Chang, Z., Chattopadhyay, S., Chen, H. F., Chen, J. H., Chen, L., Cheng, J., Cherney, M., Chikanian, A., Christie, W., Chwastowski, J., Codrington, M. J. M., Contin, G., Cramer, J. G., Crawford, H. J., Cui, X., Das, S., Leyva, A. Davila, De Silva, L. C., Debbe, R. R., Dedovich, T. G., Deng, J., Derevschikov, A. A., de Souza, R. Derradi, di Ruzza, B., Didenko, L., Dilks, C., Ding, F., Djawotho, P., Dong, X., Drachenberg, J. L., Draper, J. E., Du, C. M., Dunkelberger, L. E., Dunlop, J. C., Efimov, L. G., Engelage, J., Engle, K. S., Eppley, G., Eun, L., Evdokimov, O., Eyser, O., Fatemi, R., Fazio, S., Fedorisin, J., Filip, P., Fisyak, Y., Flores, C. E., Gagliardi, C. A., Gangadharan, D. R., Garand, D., Geurts, F., Gibson, A., Girard, M., Gliske, S., Greiner, L., Grosnick, D., Gunarathne, D. S., Guo, Y., Gupta, A., Gupta, S., Guryn, W., Haag, B., Hamed, A., Han, L-X., Haque, R., Harris, J. W., Heppelmann, S., Hirsch, A., Hoffmann, G. W., Hofman, D. J., Horvat, S., Huang, B., Huang, H. Z., Huang, X., Huck, P., Humanic, T. J., Igo, G., Jacobs, W. W., Jang, H., Judd, E. G., Kabana, S., Kalinkin, D., Kang, K., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kesich, A., Khan, Z. H., Kikola, D. P., Kisel, I., Kisiel, A., Koetke, D. D., Kollegger, T., Konzer, J., Koralt, I., Kosarzewski, L. K., Kotchenda, L., Kraishan, A. F., Kravtsov, P., Krueger, K., Kulakov, I., Kumar, L., Kycia, R. A., Lamont, M. A. C., Landgraf, J. M., Landry, K. D., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Li, C., Li, W., Li, X., Li, Y., Li, Z. M., Lisa, M. A., Liu, F., Ljubicic, T., Llope, W. J., Lomnitz, M., Longacre, R. S., Luo, X., Ma, G. L., Ma, Y. G., Mahapatra, D. P., Majka, R., Margetis, S., Markert, C., Masui, H., Matis, H. S., McDonald, D., McShane, T. S., Minaev, N. G., Mioduszewski, S., Mohanty, B., Mondal, M. M., Morozov, D. A., Mustafa, M. K., Nandi, B. K., Nasim, Md., Nayak, T. K., Nelson, J. M., Nigmatkulov, G., Nogach, L. V., Noh, S. Y., Novak, J., Nurushev, S. B., Odyniec, G., Ogawa, A., Oh, K., Ohlson, A., Okorokov, V., Oldag, E. W., Olvitt Jr., D. L., Page, B. S., Pan, Y. X., Pandit, Y., Panebratsev, Y., Pawlak, T., Pawlik, B., Pei, H., Perkins, C., Pile, P., Planinic, M., Pluta, J., Poljak, N., Poniatowska, K., Porter, J., Poskanzer, A. M., Pruthi, N. K., Przybycien, M., Putschke, J., Qiu, H., Quintero, A., Ramachandran, S., Raniwala, R., Raniwala, S., Ray, R. L., Riley, C. K., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ross, J. F., Roy, A., Ruan, L., Rusnak, J., Rusnakova, O., Sahoo, N. R., Sahu, P. K., Sakrejda, I., Salur, S., Sandacz, A., Sandweiss, J., Sangaline, E., Sarkar, A., Schambach, J., Scharenberg, R. P., Schmah, A. M., Schmidke, W. B., Schmitz, N., Seger, J., Seyboth, P., Shah, N., Shahaliev, E., Shanmuganathan, P. V., Shao, M., Sharma, B., Shen, W. Q., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Simko, M., Skoby, M. J., Smirnov, D., Smirnov, N., Solanki, D., Sorensen, P., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Stevens, J. R., Stock, R., Strikhanov, M., Stringfellow, B., Sumbera, M., Sun, X., Sun, X. M., Sun, Y., Sun, Z., Surrow, B., Svirida, D. N., Symons, T. J. M., Szelezniak, M. A., Takahashi, J., Tang, A. H., Tang, Z., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Tlusty, D., Tokarev, M., Trentalange, S., Tribble, R. E., Tribedy, P., Trzeciak, B. A., Tsai, O. D., Turnau, J., Ullrich, T., Underwood, D. G., Van Buren, G., van Nieuwenhuizen, G., Vandenbroucke, M., Vanfossen, Jr., J. A., Varma, R., Vasconcelos, G. M. S., Vasiliev, A. N., Vertesi, R., Videbæk, F., Viyogi, Y. P., Vokal, S., Vossen, A., Wada, M., Wang, F., Wang, G., Wang, H., Wang, J. S., Wang, X. L., Wang, Y., Webb, G., Webb, J. C., Westfall, G. D., Wieman, H., Wissink, S. W., Wu, Y. F., Xiao, Z., Xie, W., Xin, K., Xu, H., Xu, J., Xu, N., Xu, Q. H., Xu, Y., Xu, Z., Yan, W., Yang, C., Yang, Y., Ye, Z., Yepes, P., Yi, L., Yip, K., Yoo, I-K., Yu, N., Zbroszczyk, H., Zha, W., Zhang, J. B., Zhang, J. L., Zhang, S., Zhang, X. P., Zhang, Y., Zhang, Z. P., Zhao, F., Zhao, J., Zhong, C., Zhu, X., Zhu, Y. H., Zoulkarneeva, Y., and Zyzak, M.

Subjects
Nuclear Experiment, High Energy Physics - Experiment
Abstract

Event-by-event fluctuations of the ratio of inclusive charged to photon multiplicities at forward rapidity in Au+Au collision at $\sqrt{s_{NN}}$=200 GeV have been studied. Dominant contribution to such fluctuations is expected to come from correlated production of charged and neutral pions. We search for evidences of dynamical fluctuations of different physical origins. Observables constructed out of moments of multiplicities are used as measures of fluctuations. Mixed events and model calculations are used as baselines. Results are compared to the dynamical net-charge fluctuations measured in the same acceptance. A non-zero statistically significant signal of dynamical fluctuations is observed in excess to the model prediction when charged particles and photons are measured in the same acceptance. We find that, unlike dynamical net-charge fluctuation, charge-neutral fluctuation is not dominated by correlation due to particle decay. Results are compared to the expectations based on the generic production mechanism of pions due to isospin symmetry, for which no significant (<1%) deviation is observed., Comment: 14 pages, 6 figures

Published
2014
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5. Precision Measurement of the Longitudinal Double-spin Asymmetry for Inclusive Jet Production in Polarized Proton Collisions at $\sqrt{s}=200$ GeV

Author

STAR Collaboration, Adamczyk, L., Adkins, J. K., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alekseev, I., Alford, J., Anson, C. D., Aparin, A., Arkhipkin, D., Aschenauer, E. C., Averichev, G. S., Banerjee, A., Beavis, D. R., Bellwied, R., Bhasin, A., Bhati, A. K., Bhattarai, P., Bichsel, H., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Borowski, W., Bouchet, J., Brandin, A. V., Brovko, S. G., Bultmann, S., Bunzarov, I., Burton, T. P., Butterworth, J., Caines, H., Sanchez, M. Calderon de la Barca, Campbell, J. M., Cebra, D., Cendejas, R., Cervantes, M. C., Chaloupka, P., Chang, Z., Chattopadhyay, S., Chen, H. F., Chen, J. H., Chen, L., Cheng, J., Cherney, M., Chikanian, A., Christie, W., Chwastowski, J., Codrington, M. J. M., Contin, G., Cramer, J. G., Crawford, H. J., Cudd, A. B., Cui, X., Das, S., Leyva, A. Davila, De Silva, L. C., Debbe, R. R., Dedovich, T. G., Deng, J., Derevschikov, A. A., de Souza, R. Derradi, Dhamija, S., di Ruzza, B., Didenko, L., Dilks, C., Ding, F., Djawotho, P., Dong, X., Drachenberg, J. L., Draper, J. E., Du, C. M., Dunkelberger, L. E., Dunlop, J. C., Efimov, L. G., Engelage, J., Engle, K. S., Eppley, G., Eun, L., Evdokimov, O., Eyser, O., Fatemi, R., Fazio, S., Fedorisin, J., Filip, P., Finch, E., Fisyak, Y., Flores, C. E., Gagliardi, C. A., Gangadharan, D. R., Garand, D., Geurts, F., Gibson, A., Girard, M., Gliske, S., Greiner, L., Grosnick, D., Gunarathne, D. S., Guo, Y., Gupta, A., Gupta, S., Guryn, W., Haag, B., Hamed, A., Han, L. -X., Haque, R., Harris, J. W., Heppelmann, S., Hirsch, A., Hoffmann, G. W., Hofman, D. J., Horvat, S., Huang, B., Huang, H. Z., Huang, X., Huck, P., Humanic, T. J., Igo, G., Jacobs, W. W., Jang, H., Judd, E. G., Kabana, S., Kalinkin, D., Kang, K., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kesich, A., Khan, Z. H., Kikola, D. P., Kisel, I., Kisiel, A., Koetke, D. D., Kollegger, T., Konzer, J., Koralt, I., Kosarzewski, L. K., Kotchenda, L., Kraishan, A. F., Kravtsov, P., Krueger, K., Kulakov, I., Kumar, L., Kycia, R. A., Lamont, M. A. C., Landgraf, J. M., Landry, K. D., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., LeVine, M. J., Li, C., Li, W., Li, X., Li, Y., Li, Z. M., Lisa, M. A., Liu, F., Ljubicic, T., Llope, W. J., Lomnitz, M., Longacre, R. S., Luo, X., Ma, G. L., Ma, Y. G., Don, D. M. M. D. Madagodagettige, Mahapatra, D. P., Majka, R., Margetis, S., Markert, C., Masui, H., Matis, H. S., McDonald, D., McShane, T. S., Minaev, N. G., Mioduszewski, S., Mohanty, B., Mondal, M. M., Morozov, D. A., Mustafa, M. K., Nandi, B. K., Nasim, Md., Nayak, T. K., Nelson, J. M., Nigmatkulov, G., Nogach, L. V., Noh, S. Y., Novak, J., Nurushev, S. B., Odyniec, G., Ogawa, A., Oh, K., Ohlson, A., Okorokov, V., Oldag, E. W., Olvitt Jr., D. L., Pachr, M., Page, B. S., Pal, S. K., Pan, Y. X., Pandit, Y., Panebratsev, Y., Pawlak, T., Pawlik, B., Pei, H., Perkins, C., Peryt, W., Pile, P., Planinic, M., Pluta, J., Poljak, N., Poniatowska, K., Porter, J., Poskanzer, A. M., Pruthi, N. K., Przybycien, M., Pujahari, P. R., Putschke, J., Qiu, H., Quintero, A., Ramachandran, S., Raniwala, R., Raniwala, S., Ray, R. L., Riley, C. K., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ross, J. F., Roy, A., Ruan, L., Rusnak, J., Rusnakova, O., Sahoo, N. R., Sahu, P. K., Sakrejda, I., Salur, S., Sandweiss, J., Sangaline, E., Sarkar, A., Schambach, J., Scharenberg, R. P., Schmah, A. M., Schmidke, W. B., Schmitz, N., Seger, J., Seyboth, P., Shah, N., Shahaliev, E., Shanmuganathan, P. V., Shao, M., Sharma, B., Shen, W. Q., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Singaraju, R. N., Skoby, M. J., Smirnov, D., Smirnov, N., Solanki, D., Sorensen, P., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Stevens, J. R., Stock, R., Strikhanov, M., Stringfellow, B., Sumbera, M., Sun, X., Sun, X. M., Sun, Y., Sun, Z., Surrow, B., Svirida, D. N., Symons, T. J. M., Szelezniak, M. A., Takahashi, J., Tang, A. H., Tang, Z., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Tlusty, D., Tokarev, M., Trentalange, S., Tribble, R. E., Tribedy, P., Trzeciak, B. A., Tsai, O. D., Turnau, J., Ullrich, T., Underwood, D. G., Van Buren, G., van Nieuwenhuizen, G., Vandenbroucke, M., Vanfossen Jr., J. A., Varma, R., Vasconcelos, G. M. S., Vasiliev, A. N., Vertesi, R., Videbæk, F., Viyogi, Y. P., Vokal, S., Vossen, A., Wada, M., Wang, F., Wang, G., Wang, H., Wang, J. S., Wang, X. L., Wang, Y., Webb, G., Webb, J. C., Westfall, G. D., Wieman, H., Wissink, S. W., Witt, R., Wu, Y. F., Xiao, Z., Xie, W., Xin, K., Xu, H., Xu, J., Xu, N., Xu, Q. H., Xu, Y., Xu, Z., Yan, W., Yang, C., Yang, Y., Ye, Z., Yepes, P., Yi, L., Yip, K., Yoo, I. -K., Yu, N., Zawisza, Y., Zbroszczyk, H., Zha, W., Zhang, J. B., Zhang, J. L., Zhang, S., Zhang, X. P., Zhang, Y., Zhang, Z. P., Zhao, F., Zhao, J., Zhong, C., Zhu, X., Zhu, Y. H., Zoulkarneeva, Y., and Zyzak, M.

Subjects
High Energy Physics - Experiment, Nuclear Experiment
Abstract

We report a new high-precision measurement of the mid-rapidity inclusive jet longitudinal double-spin asymmetry, $A_{LL}$, in polarized $pp$ collisions at center-of-mass energy $\sqrt{s}=200$ GeV. The STAR data place stringent constraints on polarized parton distribution functions extracted at next-to-leading order from global analyses of inclusive deep inelastic scattering (DIS), semi-inclusive DIS, and RHIC $pp$ data. The measured asymmetries provide evidence for positive gluon polarization in the Bjorken-$x$ region $x>0.05$., Comment: 7 pages, 3 figures

Published
2014
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6. Measurement of longitudinal spin asymmetries for weak boson production in polarized proton-proton collisions at RHIC

Author

STAR Collaboration, Adamczyk, L., Adkins, J. K., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alekseev, I., Alford, J., Anson, C. D., Aparin, A., Arkhipkin, D., Aschenauer, E. C., Averichev, G. S., Balewski, J., Banerjee, A., Beavis, D. R., Bellwied, R., Bhasin, A., Bhati, A. K., Bhattarai, P., Bichsel, H., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Borowski, W., Bouchet, J., Brandin, A. V., Brovko, S. G., Bültmann, S., Bunzarov, I., Burton, T. P., Butterworth, J., Caines, H., Sánchez, M. Calderón de la Barca, Campbell, J. M., Cebra, D., Cendejas, R., Cervantes, M. C., Chaloupka, P., Chang, Z., Chattopadhyay, S., Chen, H. F., Chen, J. H., Chen, L., Cheng, J., Cherney, M., Chikanian, A., Christie, W., Chwastowski, J., Codrington, M. J. M., Contin, G., Cramer, J. G., Crawford, H. J., Cui, X., Das, S., Leyva, A. Davila, De Silva, L. C., Debbe, R. R., Dedovich, T. G., Deng, J., Derevschikov, A. A., de Souza, R. Derradi, Dhamija, S., di Ruzza, B., Didenko, L., Dilks, C., Ding, F., Djawotho, P., Dong, X., Drachenberg, J. L., Draper, J. E., Du, C. M., Dunkelberger, L. E., Dunlop, J. C., Efimov, L. G., Engelage, J., Engle, K. S., Eppley, G., Eun, L., Evdokimov, O., Eyser, O., Fatemi, R., Fazio, S., Fedorisin, J., Filip, P., Finch, E., Fisyak, Y., Flores, C. E., Gagliardi, C. A., Gangadharan, D. R., Garand, D., Geurts, F., Gibson, A., Girard, M., Gliske, S., Greiner, L., Grosnick, D., Gunarathne, D. S., Guo, Y., Gupta, A., Gupta, S., Guryn, W., Haag, B., Hamed, A., Han, L-X., Haque, R., Harris, J. W., Heppelmann, S., Hirsch, A., Hoffmann, G. W., Hofman, D. J., Horvat, S., Huang, B., Huang, H. Z., Huang, X., Huck, P., Humanic, T. J., Igo, G., Jacobs, W. W., Jang, H., Judd, E. G., Kabana, S., Kalinkin, D., Kang, K., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kesich, A., Khan, Z. H., Kikola, D. P., Kisel, I., Kisiel, A., Koetke, D. D., Kollegger, T., Konzer, J., Koralt, I., Kosarzewski, L. K., Kotchenda, L., Kraishan, A. F., Kravtsov, P., Krueger, K., Kulakov, I., Kumar, L., Kycia, R. A., Lamont, M. A. C., Landgraf, J. M., Landry, K. D., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., LeVine, M. J., Li, C., Li, W., Li, X., Li, Y., Li, Z. M., Lisa, M. A., Liu, F., Ljubicic, T., Llope, W. J., Lomnitz, M., Longacre, R. S., Luo, X., Ma, G. L., Ma, Y. G., Don, D. M. M. D. Madagodagettige, Mahapatra, D. P., Majka, R., Margetis, S., Markert, C., Masui, H., Matis, H. S., McDonald, D., McShane, T. S., Minaev, N. G., Mioduszewski, S., Mohanty, B., Mondal, M. M., Morozov, D. A., Mustafa, M. K., Nandi, B. K., Nasim, Md., Nayak, T. K., Nelson, J. M., Nigmatkulov, G., Nogach, L. V., Noh, S. Y., Novak, J., Nurushev, S. B., Odyniec, G., Ogawa, A., Oh, K., Ohlson, A., Okorokov, V., Oldag, E. W., Olvitt Jr., D. L., Pachr, M., Page, B. S., Pal, S. K., Pan, Y. X., Pandit, Y., Panebratsev, Y., Pawlak, T., Pawlik, B., Pei, H., Perkins, C., Peryt, W., Pile, P., Planinic, M., Pluta, J., Poljak, N., Poniatowska, K., Porter, J., Poskanzer, A. M., Pruthi, N. K., Przybycien, M., Pujahari, P. R., Putschke, J., Qiu, H., Quintero, A., Ramachandran, S., Raniwala, R., Raniwala, S., Ray, R. L., Riley, C. K., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ross, J. F., Roy, A., Ruan, L., Rusnak, J., Rusnakova, O., Sahoo, N. R., Sahu, P. K., Sakrejda, I., Salur, S., Sandweiss, J., Sangaline, E., Sarkar, A., Schambach, J., Scharenberg, R. P., Schmah, A. M., Schmidke, W. B., Schmitz, N., Seger, J., Seyboth, P., Shah, N., Shahaliev, E., Shanmuganathan, P. V., Shao, M., Sharma, B., Shen, W. Q., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Singaraju, R. N., Skoby, M. J., Smirnov, D., Smirnov, N., Solanki, D., Sorensen, P., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Stevens, J. R., Stock, R., Strikhanov, M., Stringfellow, B., Sumbera, M., Sun, X., Sun, X. M., Sun, Y., Sun, Z., Surrow, B., Svirida, D. N., Symons, T. J. M., Szelezniak, M. A., Takahashi, J., Tang, A. H., Tang, Z., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Tlusty, D., Tokarev, M., Trentalange, S., Tribble, R. E., Tribedy, P., Trzeciak, B. A., Tsai, O. D., Turnau, J., Ullrich, T., Underwood, D. G., Van Buren, G., van Nieuwenhuizen, G., Vandenbroucke, M., Vanfossen, Jr., J. A., Varma, R., Vasconcelos, G. M. S., Vasiliev, A. N., Vertesi, R., Videbæk, F., Viyogi, Y. P., Vokal, S., Vossen, A., Wada, M., Wang, F., Wang, G., Wang, H., Wang, J. S., Wang, X. L., Wang, Y., Webb, G., Webb, J. C., Westfall, G. D., Wieman, H., Wissink, S. W., Witt, R., Wu, Y. F., Xiao, Z., Xie, W., Xin, K., Xu, H., Xu, J., Xu, N., Xu, Q. H., Xu, Y., Xu, Z., Yan, W., Yang, C., Yang, Y., Ye, Z., Yepes, P., Yi, L., Yip, K., Yoo, I-K., Yu, N., Zawisza, Y., Zbroszczyk, H., Zha, W., Zhang, J. B., Zhang, J. L., Zhang, S., Zhang, X. P., Zhang, Y., Zhang, Z. P., Zhao, F., Zhao, J., Zhong, C., Zhu, X., Zhu, Y. H., Zoulkarneeva, Y., and Zyzak, M.

Subjects
Nuclear Experiment, High Energy Physics - Experiment
Abstract

We report measurements of single- and double- spin asymmetries for $W^{\pm}$ and $Z/\gamma^*$ boson production in longitudinally polarized $p+p$ collisions at $\sqrt{s} = 510$ GeV by the STAR experiment at RHIC. The asymmetries for $W^{\pm}$ were measured as a function of the decay lepton pseudorapidity, which provides a theoretically clean probe of the proton's polarized quark distributions at the scale of the $W$ mass. The results are compared to theoretical predictions, constrained by recent polarized deep inelastic scattering measurements, and show a preference for a sizable, positive up antiquark polarization in the range $0.05

Published
2014
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7. Observation of $D^0$ meson nuclear modifications in Au+Au collisions at $\sqrt{s_{_{\mathrm{NN}}}}$ = 200 GeV

Author

Adamczyk, L., Adkins, J. K., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alekseev, I., Alford, J., Anson, C. D., Aparin, A., Arkhipkin, D., Aschenauer, E. C., Averichev, G. S., Banerjee, A., Beavis, D. R., Bellwied, R., Bhasin, A., Bhati, A. K., Bhattarai, P., Bichsel, H., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Borowski, W., Bouchet, J., Brandin, A. V., Brovko, S. G., Bültmann, S., Bunzarov, I., Burton, T. P., Butterworth, J., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Cendejas, R., Cervantes, M. C., Chaloupka, P., Chang, Z., Chattopadhyay, S., Chen, H. F., Chen, J. H., Chen, L., Cheng, J., Cherney, M., Chikanian, A., Christie, W., Chwastowski, J., Codrington, M. J. M., Contin, G., Cramer, J. G., Crawford, H. J., Cui, X., Das, S., Leyva, A. Davila, De Silva, L. C., Debbe, R. R., Dedovich, T. G., Deng, J., Derevschikov, A. A., de Souza, R. Derradi, Dhamija, S., di Ruzza, B., Didenko, L., Dilks, C., Ding, F., Djawotho, P., Dong, X., Drachenberg, J. L., Draper, J. E., Du, C. M., Dunkelberger, L. E., Dunlop, J. C., Efimov, L. G., Engelage, J., Engle, K. S., Eppley, G., Eun, L., Evdokimov, O., Eyser, O., Fatemi, R., Fazio, S., Fedorisin, J., Filip, P., Finch, E., Fisyak, Y., Flores, C. E., Gagliardi, C. A., Gangadharan, D. R., Garand, D., Geurts, F., Gibson, A., Girard, M., Gliske, S., Greiner, L., Grosnick, D., Gunarathne, D. S., Guo, Y., Gupta, A., Gupta, S., Guryn, W., Haag, B., Hamed, A., Han, L-X., Haque, R., Harris, J. W., Heppelmann, S., Hirsch, A., Hoffmann, G. W., Hofman, D. J., Horvat, S., Huang, B., Huang, H. Z., Huang, X., Huck, P., Humanic, T. J., Igo, G., Jacobs, W. W., Jang, H., Judd, E. G., Kabana, S., Kalinkin, D., Kang, K., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kesich, A., Khan, Z. H., Kikola, D. P., Kisel, I., Kisiel, A., Koetke, D. D., Kollegger, T., Konzer, J., Koralt, I., Kosarzewski, L. K., Kotchenda, L., Kraishan, A. F., Kravtsov, P., Krueger, K., Kulakov, I., Kumar, L., Kycia, R. A., Lamont, M. A. C., Landgraf, J. M., Landry, K. D., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., LeVine, M. J., Li, C., Li, W., Li, X., Li, Y., Li, Z. M., Lisa, M. A., Liu, F., Ljubicic, T., Llope, W. J., Lomnitz, M., Longacre, R. S., Luo, X., Ma, G. L., Ma, Y. G., Don, D. M. M. D. Madagodagettige, Mahapatra, D. P., Majka, R., Margetis, S., Markert, C., Masui, H., Matis, H. S., McDonald, D., McShane, T. S., Minaev, N. G., Mioduszewski, S., Mohanty, B., Mondal, M. M., Morozov, D. A., Mustafa, M. K., Nandi, B. K., Nasim, Md., Nayak, T. K., Nelson, J. M., Nigmatkulov, G., Nogach, L. V., Noh, S. Y., Novak, J., Nurushev, S. B., Odyniec, G., Ogawa, A., Oh, K., Ohlson, A., Okorokov, V., Oldag, E. W., Olvitt Jr., D. L., Pachr, M., Page, B. S., Pal, S. K., Pan, Y. X., Pandit, Y., Panebratsev, Y., Pawlak, T., Pawlik, B., Pei, H., Perkins, C., Peryt, W., Pile, P., Planinic, M., Pluta, J., Poljak, N., Poniatowska, K., Porter, J., Poskanzer, A. M., Pruthi, N. K., Przybycien, M., Pujahari, P. R., Putschke, J., Qiu, H., Quintero, A., Ramachandran, S., Raniwala, R., Raniwala, S., Ray, R. L., Riley, C. K., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ross, J. F., Roy, A., Ruan, L., Rusnak, J., Rusnakova, O., Sahoo, N. R., Sahu, P. K., Sakrejda, I., Salur, S., Sandweiss, J., Sangaline, E., Sarkar, A., Schambach, J., Scharenberg, R. P., Schmah, A. M., Schmidke, W. B., Schmitz, N., Seger, J., Seyboth, P., Shah, N., Shahaliev, E., Shanmuganathan, P. V., Shao, M., Sharma, B., Shen, W. Q., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Singaraju, R. N., Skoby, M. J., Smirnov, D., Smirnov, N., Solanki, D., Sorensen, P., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Stevens, J. R., Stock, R., Strikhanov, M., Stringfellow, B., Sumbera, M., Sun, X., Sun, X. M., Sun, Y., Sun, Z., Surrow, B., Svirida, D. N., Symons, T. J. M., Szelezniak, M. A., Takahashi, J., Tang, A. H., Tang, Z., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Tlusty, D., Tokarev, M., Trentalange, S., Tribble, R. E., Tribedy, P., Trzeciak, B. A., Tsai, O. D., Turnau, J., Ullrich, T., Underwood, D. G., Van Buren, G., van Nieuwenhuizen, G., Vandenbroucke, M., Vanfossen, Jr., J. A., Varma, R., Vasconcelos, G. M. S., Vasiliev, A. N., Vertesi, R., Videbæk, F., Viyogi, Y. P., Vokal, S., Vossen, A., Wada, M., Wang, F., Wang, G., Wang, H., Wang, J. S., Wang, X. L., Wang, Y., Webb, G., Webb, J. C., Westfall, G. D., Wieman, H., Wissink, S. W., Witt, R., Wu, Y. F., Xiao, Z., Xie, W., Xin, K., Xu, H., Xu, J., Xu, N., Xu, Q. H., Xu, Y., Xu, Z., Yan, W., Yang, C., Yang, Y., Ye, Z., Yepes, P., Yi, L., Yip, K., Yoo, I-K., Yu, N., Zawisza, Y., Zbroszczyk, H., Zha, W., Zhang, J. B., Zhang, J. L., Zhang, S., Zhang, X. P., Zhang, Y., Zhang, Z. P., Zhao, F., Zhao, J., Zhong, C., Zhu, X., Zhu, Y. H., Zoulkarneeva, Y., and Zyzak, M.

Subjects
Nuclear Experiment
Abstract

We report the first measurement of charmed-hadron ($D^0$) production via the hadronic decay channel ($D^0\rightarrow K^- + \pi^+$) in Au+Au collisions at $\sqrt{s_{_{\mathrm{NN}}}}$ = 200\,GeV with the STAR experiment. The charm production cross-section per nucleon-nucleon collision at mid-rapidity scales with the number of binary collisions, $N_{bin}$, from $p$+$p$ to central Au+Au collisions. The $D^0$ meson yields in central Au+Au collisions are strongly suppressed compared to those in $p$+$p$ scaled by $N_{bin}$, for transverse momenta $p_{T}>3$ GeV/$c$, demonstrating significant energy loss of charm quarks in the hot and dense medium. An enhancement at intermediate $p_{T}$ is also observed. Model calculations including strong charm-medium interactions and coalescence hadronization describe our measurements., Comment: 7 pages including author list, 4 figures, submit to PRL with revised version

Published
2014
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8. Beam-energy dependence of charge separation along the magnetic field in Au+Au collisions at RHIC

Author

STAR Collaboration, Adamczyk, L., Adkins, J. K., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alekseev, I., Alford, J., Anson, C. D., Aparin, A., Arkhipkin, D., Aschenauer, E. C., Averichev, G. S., Banerjee, A., Beavis, D. R., Bellwied, R., Bhasin, A., Bhati, A. K., Bhattarai, P., Bichsel, H., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Borowski, W., Bouchet, J., Brandin, A. V., Brovko, S. G., Bültmann, S., Bunzarov, I., Burton, T. P., Butterworth, J., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Cendejas, R., Cervantes, M. C., Chaloupka, P., Chang, Z., Chattopadhyay, S., Chen, H. F., Chen, J. H., Chen, L., Cheng, J., Cherney, M., Chikanian, A., Christie, W., Chwastowski, J., Codrington, M. J. M., Contin, G., Cramer, J. G., Crawford, H. J., Cui, X., Das, S., Leyva, A. Davila, De Silva, L. C., Debbe, R. R., Dedovich, T. G., Deng, J., Derevschikov, A. A., de Souza, R. Derradi, Dhamija, S., di Ruzza, B., Didenko, L., Dilks, C., Ding, F., Djawotho, P., Dong, X., Drachenberg, J. L., Draper, J. E., Du, C. M., Dunkelberger, L. E., Dunlop, J. C., Efimov, L. G., Engelage, J., Engle, K. S., Eppley, G., Eun, L., Evdokimov, O., Eyser, O., Fatemi, R., Fazio, S., Fedorisin, J., Filip, P., Finch, E., Fisyak, Y., Flores, C. E., Gagliardi, C. A., Gangadharan, D. R., Garand, D., Geurts, F., Gibson, A., Girard, M., Gliske, S., Greiner, L., Grosnick, D., Gunarathne, D. S., Guo, Y., Gupta, A., Gupta, S., Guryn, W., Haag, B., Hamed, A., Han, L-X., Haque, R., Harris, J. W., Heppelmann, S., Hirsch, A., Hoffmann, G. W., Hofman, D. J., Horvat, S., Huang, B., Huang, H. Z., Huang, X., Huck, P., Humanic, T. J., Igo, G., Jacobs, W. W., Jang, H., Judd, E. G., Kabana, S., Kalinkin, D., Kang, K., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kesich, A., Khan, Z. H., Kikola, D. P., Kisel, I., Kisiel, A., Koetke, D. D., Kollegger, T., Konzer, J., Koralt, I., Kosarzewski, L. K., Kotchenda, L., Kraishan, A. F., Kravtsov, P., Krueger, K., Kulakov, I., Kumar, L., Kycia, R. A., Lamont, M. A. C., Landgraf, J. M., Landry, K. D., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., LeVine, M. J., Li, C., Li, W., Li, X., Li, Y., Li, Z. M., Lisa, M. A., Liu, F., Ljubicic, T., Llope, W. J., Lomnitz, M., Longacre, R. S., Luo, X., Ma, G. L., Ma, Y. G., Don, D. M. M. D. Madagodagettige, Mahapatra, D. P., Majka, R., Margetis, S., Markert, C., Masui, H., Matis, H. S., McDonald, D., McShane, T. S., Minaev, N. G., Mioduszewski, S., Mohanty, B., Mondal, M. M., Morozov, D. A., Mustafa, M. K., Nandi, B. K., Nasim, Md., Nayak, T. K., Nelson, J. M., Nigmatkulov, G., Nogach, L. V., Noh, S. Y., Novak, J., Nurushev, S. B., Odyniec, G., Ogawa, A., Oh, K., Ohlson, A., Okorokov, V., Oldag, E. W., Olvitt Jr., D. L., Pachr, M., Page, B. S., Pal, S. K., Pan, Y. X., Pandit, Y., Panebratsev, Y., Pawlak, T., Pawlik, B., Pei, H., Perkins, C., Peryt, W., Pile, P., Planinic, M., Pluta, J., Poljak, N., Poniatowska, K., Porter, J., Poskanzer, A. M., Pruthi, N. K., Przybycien, M., Pujahari, P. R., Putschke, J., Qiu, H., Quintero, A., Ramachandran, S., Raniwala, R., Raniwala, S., Ray, R. L., Riley, C. K., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ross, J. F., Roy, A., Ruan, L., Rusnak, J., Rusnakova, O., Sahoo, N. R., Sahu, P. K., Sakrejda, I., Salur, S., Sandweiss, J., Sangaline, E., Sarkar, A., Schambach, J., Scharenberg, R. P., Schmah, A. M., Schmidke, W. B., Schmitz, N., Seger, J., Seyboth, P., Shah, N., Shahaliev, E., Shanmuganathan, P. V., Shao, M., Sharma, B., Shen, W. Q., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Singaraju, R. N., Skoby, M. J., Smirnov, D., Smirnov, N., Solanki, D., Sorensen, P., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Stevens, J. R., Stock, R., Strikhanov, M., Stringfellow, B., Sumbera, M., Sun, X., Sun, X. M., Sun, Y., Sun, Z., Surrow, B., Svirida, D. N., Symons, T. J. M., Szelezniak, M. A., Takahashi, J., Tang, A. H., Tang, Z., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Tlusty, D., Tokarev, M., Trentalange, S., Tribble, R. E., Tribedy, P., Trzeciak, B. A., Tsai, O. D., Turnau, J., Ullrich, T., Underwood, D. G., Van Buren, G., van Nieuwenhuizen, G., Vandenbroucke, M., Vanfossen, Jr., J. A., Varma, R., Vasconcelos, G. M. S., Vasiliev, A. N., Vertesi, R., Videbæk, F., Viyogi, Y. P., Vokal, S., Vossen, A., Wada, M., Wang, F., Wang, G., Wang, H., Wang, J. S., Wang, X. L., Wang, Y., Webb, G., Webb, J. C., Westfall, G. D., Wieman, H., Wissink, S. W., Witt, R., Wu, Y. F., Xiao, Z., Xie, W., Xin, K., Xu, H., Xu, J., Xu, N., Xu, Q. H., Xu, Y., Xu, Z., Yan, W., Yang, C., Yang, Y., Ye, Z., Yepes, P., Yi, L., Yip, K., Yoo, I-K., Yu, N., Zawisza, Y., Zbroszczyk, H., Zha, W., Zhang, J. B., Zhang, J. L., Zhang, S., Zhang, X. P., Zhang, Y., Zhang, Z. P., Zhao, F., Zhao, J., Zhong, C., Zhu, X., Zhu, Y. H., Zoulkarneeva, Y., and Zyzak, M.

Subjects
Nuclear Experiment
Abstract

Local parity-odd domains are theorized to form inside a Quark-Gluon-Plasma (QGP) which has been produced in high-energy heavy-ion collisions. The local parity-odd domains manifest themselves as charge separation along the magnetic field axis via the chiral magnetic effect (CME). The experimental observation of charge separation has previously been reported for heavy-ion collisions at the top RHIC energies. In this paper, we present the results of the beam-energy dependence of the charge correlations in Au+Au collisions at midrapidity for center-of-mass energies of 7.7, 11.5, 19.6, 27, 39 and 62.4 GeV from the STAR experiment. After background subtraction, the signal gradually reduces with decreased beam energy, and tends to vanish by 7.7 GeV. The implications of these results for the CME will be discussed., Comment: 6 pages, 4 figures, accepted by Phys. Rev. Lett (more model comparisons have been added in version 2)

Published
2014
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9. Beam energy dependent two-pion interferometry and the freeze-out eccentricity of pions in heavy ion collisions at STAR

Author

STAR Collaboration, Adamczyk, L., Adkins, J. K., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alekseev, I., Alford, J., Anson, C. D., Aparin, A., Arkhipkin, D., Aschenauer, E. C., Averichev, G. S., Banerjee, A., Beavis, D. R., Bellwied, R., Bhasin, A., Bhati, A. K., Bhattarai, P., Bichsel, H., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Borowski, W., Bouchet, J., Brandin, A. V., Brovko, S. G., Bültmann, S., Bunzarov, I., Burton, T. P., Butterworth, J., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Cendejas, R., Cervantes, M. C., Chaloupka, P., Chang, Z., Chattopadhyay, S., Chen, H. F., Chen, J. H., Chen, L., Cheng, J., Cherney, M., Chikanian, A., Christie, W., Chwastowski, J., Codrington, M. J. M., Contin, G., Cramer, J. G., Crawford, H. J., Cui, X., Das, S., Leyva, A. Davila, De Silva, L. C., Debbe, R. R., Dedovich, T. G., Deng, J., Derevschikov, A. A., de Souza, R. Derradi, Dhamija, S., di Ruzza, B., Didenko, L., Dilks, C., Ding, F., Djawotho, P., Dong, X., Drachenberg, J. L., Draper, J. E., Du, C. M., Dunkelberger, L. E., Dunlop, J. C., Efimov, L. G., Engelage, J., Engle, K. S., Eppley, G., Eun, L., Evdokimov, O., Eyser, O., Fatemi, R., Fazio, S., Fedorisin, J., Filip, P., Finch, E., Fisyak, Y., Flores, C. E., Gagliardi, C. A., Gangadharan, D. R., Garand, D., Geurts, F., Gibson, A., Girard, M., Gliske, S., Greiner, L., Grosnick, D., Gunarathne, D. S., Guo, Y., Gupta, A., Gupta, S., Guryn, W., Haag, B., Hamed, A., Han, L-X., Haque, R., Harris, J. W., Heppelmann, S., Hirsch, A., Hoffmann, G. W., Hofman, D. J., Horvat, S., Huang, B., Huang, H. Z., Huang, X., Huck, P., Humanic, T. J., Igo, G., Jacobs, W. W., Jang, H., Judd, E. G., Kabana, S., Kalinkin, D., Kang, K., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kesich, A., Khan, Z. H., Kikola, D. P., Kisel, I., Kisiel, A., Koetke, D. D., Kollegger, T., Konzer, J., Koralt, I., Kosarzewski, L. K., Kotchenda, L., Kraishan, A. F., Kravtsov, P., Krueger, K., Kulakov, I., Kumar, L., Kycia, R. A., Lamont, M. A. C., Landgraf, J. M., Landry, K. D., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., LeVine, M. J., Li, C., Li, W., Li, X., Li, Y., Li, Z. M., Lisa, M. A., Liu, F., Ljubicic, T., Llope, W. J., Lomnitz, M., Longacre, R. S., Luo, X., Ma, G. L., Ma, Y. G., Don, D. M. M. D. Madagodagettige, Mahapatra, D. P., Majka, R., Margetis, S., Markert, C., Masui, H., Matis, H. S., McDonald, D., McShane, T. S., Minaev, N. G., Mioduszewski, S., Mohanty, B., Mondal, M. M., Morozov, D. A., Mustafa, M. K., Nandi, B. K., Nasim, Md., Nayak, T. K., Nelson, J. M., Nigmatkulov, G., Nogach, L. V., Noh, S. Y., Novak, J., Nurushev, S. B., Odyniec, G., Ogawa, A., Oh, K., Ohlson, A., Okorokov, V., Oldag, E. W., Olvitt Jr., D. L., Pachr, M., Page, B. S., Pal, S. K., Pan, Y. X., Pandit, Y., Panebratsev, Y., Pawlak, T., Pawlik, B., Pei, H., Perkins, C., Peryt, W., Pile, P., Planinic, M., Pluta, J., Poljak, N., Poniatowska, K., Porter, J., Poskanzer, A. M., Pruthi, N. K., Przybycien, M., Pujahari, P. R., Putschke, J., Qiu, H., Quintero, A., Ramachandran, S., Raniwala, R., Raniwala, S., Ray, R. L., Riley, C. K., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ross, J. F., Roy, A., Ruan, L., Rusnak, J., Rusnakova, O., Sahoo, N. R., Sahu, P. K., Sakrejda, I., Salur, S., Sandweiss, J., Sangaline, E., Sarkar, A., Schambach, J., Scharenberg, R. P., Schmah, A. M., Schmidke, W. B., Schmitz, N., Seger, J., Seyboth, P., Shah, N., Shahaliev, E., Shanmuganathan, P. V., Shao, M., Sharma, B., Shen, W. Q., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Singaraju, R. N., Skoby, M. J., Smirnov, D., Smirnov, N., Solanki, D., Sorensen, P., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Stevens, J. R., Stock, R., Strikhanov, M., Stringfellow, B., Sumbera, M., Sun, X., Sun, X. M., Sun, Y., Sun, Z., Surrow, B., Svirida, D. N., Symons, T. J. M., Szelezniak, M. A., Takahashi, J., Tang, A. H., Tang, Z., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Tlusty, D., Tokarev, M., Trentalange, S., Tribble, R. E., Tribedy, P., Trzeciak, B. A., Tsai, O. D., Turnau, J., Ullrich, T., Underwood, D. G., Van Buren, G., van Nieuwenhuizen, G., Vandenbroucke, M., Vanfossen, Jr., J. A., Varma, R., Vasconcelos, G. M. S., Vasiliev, A. N., Vertesi, R., Videbæk, F., Viyogi, Y. P., Vokal, S., Vossen, A., Wada, M., Wang, F., Wang, G., Wang, H., Wang, J. S., Wang, X. L., Wang, Y., Webb, G., Webb, J. C., Westfall, G. D., Wieman, H., Wissink, S. W., Witt, R., Wu, Y. F., Xiao, Z., Xie, W., Xin, K., Xu, H., Xu, J., Xu, N., Xu, Q. H., Xu, Y., Xu, Z., Yan, W., Yang, C., Yang, Y., Ye, Z., Yepes, P., Yi, L., Yip, K., Yoo, I-K., Yu, N., Zawisza, Y., Zbroszczyk, H., Zha, W., Zhang, J. B., Zhang, J. L., Zhang, S., Zhang, X. P., Zhang, Y., Zhang, Z. P., Zhao, F., Zhao, J., Zhong, C., Zhu, X., Zhu, Y. H., Zoulkarneeva, Y., and Zyzak, M.

Subjects
Nuclear Experiment
Abstract

We present results of analyses of two-pion interferometry in Au+Au collisions at $\sqrt{s_{NN}}$ = 7.7, 11.5, 19.6, 27, 39, 62.4 and 200 GeV measured in the STAR detector as part of the RHIC Beam Energy Scan program. The extracted correlation lengths (HBT radii) are studied as a function of beam energy, azimuthal angle relative to the reaction plane, centrality, and transverse mass ($m_{T}$) of the particles. The azimuthal analysis allows extraction of the eccentricity of the entire fireball at kinetic freeze-out. The energy dependence of this observable is expected to be sensitive to changes in the equation of state. A new global fit method is studied as an alternate method to directly measure the parameters in the azimuthal analysis. The eccentricity shows a monotonic decrease with beam energy that is qualitatively consistent with the trend from all model predictions and quantitatively consistent with a hadronic transport model., Comment: 27 pages; 27 figures

Published
2014
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10. Beam-Energy Dependence of Directed Flow of Protons, Antiprotons and Pions in Au+Au Collisions

Author

STAR Collaboration, Adamczyk, L., Adkins, J. K., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alekseev, I., Alford, J., Anson, C. D., Aparin, A., Arkhipkin, D., Aschenauer, E. C., Averichev, G. S., Banerjee, A., Beavis, D. R., Bellwied, R., Bhasin, A., Bhati, A. K., Bhattarai, P., Bichsel, H., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Borowski, W., Bouchet, J., Brandin, A. V., Brovko, S. G., Bültmann, S., Bunzarov, I., Burton, T. P., Butterworth, J., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Cendejas, R., Cervantes, M. C., Chaloupka, P., Chang, Z., Chattopadhyay, S., Chen, H. F., Chen, J. H., Chen, L., Cheng, J., Cherney, M., Chikanian, A., Christie, W., Chwastowski, J., Codrington, M. J. M., Contin, G., Cramer, J. G., Crawford, H. J., Cui, X., Das, S., Leyva, A. Davila, De Silva, L. C., Debbe, R. R., Dedovich, T. G., Deng, J., Derevschikov, A. A., de Souza, R. Derradi, Dhamija, S., di Ruzza, B., Didenko, L., Dilks, C., Ding, F., Djawotho, P., Dong, X., Drachenberg, J. L., Draper, J. E., Du, C. M., Dunkelberger, L. E., Dunlop, J. C., Efimov, L. G., Engelage, J., Engle, K. S., Eppley, G., Eun, L., Evdokimov, O., Eyser, O., Fatemi, R., Fazio, S., Fedorisin, J., Filip, P., Finch, E., Fisyak, Y., Flores, C. E., Gagliardi, C. A., Gangadharan, D. R., Garand, D., Geurts, F., Gibson, A., Girard, M., Gliske, S., Greiner, L., Grosnick, D., Gunarathne, D. S., Guo, Y., Gupta, A., Gupta, S., Guryn, W., Haag, B., Hamed, A., Han, L-X., Haque, R., Harris, J. W., Heppelmann, S., Hirsch, A., Hoffmann, G. W., Hofman, D. J., Horvat, S., Huang, B., Huang, H. Z., Huang, X., Huck, P., Humanic, T. J., Igo, G., Jacobs, W. W., Jang, H., Judd, E. G., Kabana, S., Kalinkin, D., Kang, K., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kesich, A., Khan, Z. H., Kikola, D. P., Kisel, I., Kisiel, A., Koetke, D. D., Kollegger, T., Konzer, J., Koralt, I., Kotchenda, L., Kraishan, A. F., Kravtsov, P., Krueger, K., Kulakov, I., Kumar, L., Kycia, R. A., Lamont, M. A. C., Landgraf, J. M., Landry, K. D., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., LeVine, M. J., Li, C., Li, W., Li, X., Li, Y., Li, Z. M., Lisa, M. A., Liu, F., Ljubicic, T., Llope, W. J., Lomnitz, M., Longacre, R. S., Luo, X., Ma, G. L., Ma, Y. G., Don, D. M. M. D. Madagodagettige, Mahapatra, D. P., Majka, R., Margetis, S., Markert, C., Masui, H., Matis, H. S., McDonald, D., McShane, T. S., Minaev, N. G., Mioduszewski, S., Mohanty, B., Mondal, M. M., Morozov, D. A., Mustafa, M. K., Nandi, B. K., Nasim, Md., Nayak, T. K., Nelson, J. M., Nigmatkulov, G., Nogach, L. V., Noh, S. Y., Novak, J., Nurushev, S. B., Odyniec, G., Ogawa, A., Oh, K., Ohlson, A., Okorokov, V., Oldag, E. W., Olvitt Jr., D. L., Pachr, M., Page, B. S., Pal, S. K., Pan, Y. X., Pandit, Y., Panebratsev, Y., Pawlak, T., Pawlik, B., Pei, H., Perkins, C., Peryt, W., Pile, P., Planinic, M., Pluta, J., Poljak, N., Porter, J., Poskanzer, A. M., Pruthi, N. K., Przybycien, M., Pujahari, P. R., Putschke, J., Qiu, H., Quintero, A., Ramachandran, S., Raniwala, R., Raniwala, S., Ray, R. L., Riley, C. K., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ross, J. F., Roy, A., Ruan, L., Rusnak, J., Rusnakova, O., Sahoo, N. R., Sahu, P. K., Sakrejda, I., Salur, S., Sandweiss, J., Sangaline, E., Sarkar, A., Schambach, J., Scharenberg, R. P., Schmah, A. M., Schmidke, W. B., Schmitz, N., Seger, J., Seyboth, P., Shah, N., Shahaliev, E., Shanmuganathan, P. V., Shao, M., Sharma, B., Shen, W. Q., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Singaraju, R. N., Skoby, M. J., Smirnov, D., Smirnov, N., Solanki, D., Sorensen, P., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Stevens, J. R., Stock, R., Strikhanov, M., Stringfellow, B., Sumbera, M., Sun, X., Sun, X. M., Sun, Y., Sun, Z., Surrow, B., Svirida, D. N., Symons, T. J. M., Szelezniak, M. A., Takahashi, J., Tang, A. H., Tang, Z., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Tlusty, D., Tokarev, M., Trentalange, S., Tribble, R. E., Tribedy, P., Trzeciak, B. A., Tsai, O. D., Turnau, J., Ullrich, T., Underwood, D. G., Van Buren, G., van Nieuwenhuizen, G., Vandenbroucke, M., Vanfossen, Jr., J. A., Varma, R., Vasconcelos, G. M. S., Vasiliev, A. N., Vertesi, R., Videbæk, F., Viyogi, Y. P., Vokal, S., Vossen, A., Wada, M., Wang, F., Wang, G., Wang, H., Wang, J. S., Wang, X. L., Wang, Y., Webb, G., Webb, J. C., Westfall, G. D., Wieman, H., Wissink, S. W., Witt, R., Wu, Y. F., Xiao, Z., Xie, W., Xin, K., Xu, H., Xu, J., Xu, N., Xu, Q. H., Xu, Y., Xu, Z., Yan, W., Yang, C., Yang, Y., Ye, Z., Yepes, P., Yi, L., Yip, K., Yoo, I-K., Yu, N., Zawisza, Y., Zbroszczyk, H., Zha, W., Zhang, J. B., Zhang, J. L., Zhang, S., Zhang, X. P., Zhang, Y., Zhang, Z. P., Zhao, F., Zhao, J., Zhong, C., Zhu, X., Zhu, Y. H., Zoulkarneeva, Y., and Zyzak, M.

Subjects
Nuclear Experiment, High Energy Physics - Experiment
Abstract

Rapidity-odd directed flow($v_1$) measurements for charged pions, protons and antiprotons near mid-rapidity ($y=0$) are reported in $\sqrt{s_{NN}} =$ 7.7, 11.5, 19.6, 27, 39, 62.4 and 200 GeV Au + Au collisions as recorded by the STAR detector at the Relativistic Heavy Ion Collider (RHIC). At intermediate impact parameters, the proton and net-proton slope parameter $dv_1/dy|_{y=0}$ shows a minimum between 11.5 and 19.6 GeV. In addition, the net-proton $dv_1/dy|_{y=0}$ changes sign twice between 7.7 and 39 GeV. The proton and net-proton results qualitatively resemble predictions of a hydrodynamic model with a first-order phase transition from hadronic matter to deconfined matter, and differ from hadronic transport calculations., Comment: Post-referee version, accepted by PRL. Fig. 2 now includes panels for 62.4 and 200 GeV

Published
2014
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11. Dielectron Mass Spectra from Au+Au Collisions at $\sqrt{s_{\rm NN}}$ = 200 GeV

Author

STAR Collaboration, Adamczyk, L., Adkins, J. K., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alekseev, I., Alford, J., Anson, C. D., Aparin, A., Arkhipkin, D., Aschenauer, E. C., Averichev, G. S., Banerjee, A., Beavis, D. R., Bellwied, R., Bhasin, A., Bhati, A. K., Bhattarai, P., Bichsel, H., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Borowski, W., Bouchet, J., Brandin, A. V., Brovko, S. G., Bültmann, S., Bunzarov, I., Burton, T. P., Butterworth, J., Caines, H., Sánchez, M. Calderóndze la Barca, Cebra, D., Cendejas, R., Cervantes, M. C., Chaloupka, P., Chang, Z., Chattopadhyay, S., Chen, H. F., Chen, J. H., Chen, L., Cheng, J., Cherney, M., Chikanian, A., Christie, W., Chwastowski, J., Codrington, M. J. M., Contin, G., Cramer, J. G., Crawford, H. J., Cui, X., Das, S., Leyva, A. Davila, De Silva, L. C., Debbe, R. R., Dedovich, T. G., Deng, J., Derevschikov, A. A., de Souza, R. Derradi, Dhamija, S., di Ruzza, B., Didenko, L., Dilks, C., Ding, F., Djawotho, P., Dong, X., Drachenberg, J. L., Draper, J. E., Du, C. M., Dunkelberger, L. E., Dunlop, J. C., Efimov, L. G., Engelage, J., Engle, K. S., Eppley, G., Eun, L., Evdokimov, O., Fatemi, R., Fazio, S., Fedorisin, J., Filip, P., Finch, E., Fisyak, Y., Flores, C. E., Gagliardi, C. A., Gangadharan, D. R., Garand, D., Geurts, F., Gibson, A., Girard, M., Gliske, S., Greiner, L., Grosnick, D., Gunarathne, D. S., Guo, Y., Gupta, A., Gupta, S., Guryn, W., Haag, B., Hajkova, O., Hamed, A., Han, L-X., Haque, R., Harris, J. W., Heppelmann, S., Hirsch, A., Hoffmann, G. W., Hofman, D. J., Horvat, S., Huang, B., Huang, H. Z., Huang, X., Huck, P., Humanic, T. J., Igo, G., Jacobs, W. W., Jang, H., Judd, E. G., Kabana, S., Kalinkin, D., Kang, K., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kesich, A., Khan, Z. H., Kikola, D. P., Kisel, I., Kisiel, A., Koetke, D. D., Kollegger, T., Konzer, J., Koralt, I., Kotchenda, L., Kraishan, A. F., Kravtsov, P., Krueger, K., Kulakov, I., Kumar, L., Kycia, R. A., Lamont, M. A. C., Landgraf, J. M., Landry, K. D., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., LeVine, M. J., Li, C., Li, W., Li, X., Li, Y., Li, Z. M., Lisa, M. A., Liu, F., Ljubicic, T., Llope, W. J., Lomnitz, M., Longacre, R. S., Luo, X., Ma, G. L., Ma, Y. G., Don, D. M. M. D. Madagodagettige, Mahapatra, D. P., Majka, R., Margetis, S., Markert, C., Masui, H., Matis, H. S., McDonald, D., McShane, T. S., Minaev, N. G., Mioduszewski, S., Mohanty, B., Mondal, M. M., Morozov, D. A., Mustafa, M. K., Nandi, B. K., Nasim, Md., Nayak, T. K., Nelson, J. M., Nigmatkulov, G., Nogach, L. V., Noh, S. Y., Novak, J., Nurushev, S. B., Odyniec, G., Ogawa, A., Oh, K., Ohlson, A., Okorokov, V., Oldag, E. W., Olvitt Jr., D. L., Pachr, M., Page, B. S., Pal, S. K., Pan, Y. X., Pandit, Y., Panebratsev, Y., Pawlak, T., Pawlik, B., Pei, H., Perkins, C., Peryt, W., Pile, P., Planinic, M., Pluta, J., Poljak, N., Porter, J., Poskanzer, A. M., Pruthi, N. K., Przybycien, M., Pujahari, P. R., Putschke, J., Qiu, H., Quintero, A., Ramachandran, S., Raniwala, R., Raniwala, S., Ray, R. L., Riley, C. K., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ross, J. F., Roy, A., Ruan, L., Rusnak, J., Sahoo, N. R., Sahu, P. K., Sakrejda, I., Salur, S., Sandweiss, J., Sangaline, E., Sarkar, A., Schambach, J., Scharenberg, R. P., Schmah, A. M., Schmidke, W. B., Schmitz, N., Seger, J., Seyboth, P., Shah, N., Shahaliev, E., Shanmuganathan, P. V., Shao, M., Sharma, B., Shen, W. Q., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Singaraju, R. N., Skoby, M. J., Smirnov, D., Smirnov, N., Solanki, D., Sorensen, P., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Stevens, J. R., Stock, R., Strikhanov, M., Stringfellow, B., Sumbera, M., Sun, X., Sun, X. M., Sun, Y., Sun, Z., Surrow, B., Svirida, D. N., Symons, T. J. M., Szelezniak, M. A., Takahashi, J., Tang, A. H., Tang, Z., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Tlusty, D., Tokarev, M., Trentalange, S., Tribble, R. E., Tribedy, P., Trzeciak, B. A., Tsai, O. D., Turnau, J., Ullrich, T., Underwood, D. G., Van Buren, G., van Nieuwenhuizen, G., Vandenbroucke, M., Vanfossen, Jr., J. A., Varma, R., Vasconcelos, G. M. S., Vasiliev, A. N., Vertesi, R., Videbæk, F., Viyogi, Y. P., Vokal, S., Vossen, A., Wada, M., Wang, F., Wang, G., Wang, H., Wang, J. S., Wang, X. L., Wang, Y., Webb, G., Webb, J. C., Westfall, G. D., Wieman, H., Wissink, S. W., Witt, R., Wu, Y. F., Xiao, Z., Xie, W., Xin, K., Xu, H., Xu, J., Xu, N., Xu, Q. H., Xu, Y., Xu, Z., Yan, W., Yang, C., Yang, Y., Ye, Z., Yepes, P., Yi, L., Yip, K., Yoo, I-K., Yu, N., Zawisza, Y., Zbroszczyk, H., Zha, W., Zhang, J. B., Zhang, J. L., Zhang, S., Zhang, X. P., Zhang, Y., Zhang, Z. P., Zhao, F., Zhao, J., Zhong, C., Zhu, X., Zhu, Y. H., Zoulkarneeva, Y., and Zyzak, M.

Subjects
High Energy Physics - Experiment, Nuclear Experiment
Abstract

We report the STAR measurements of dielectron ($e^+e^-$) production at midrapidity ($|y_{ee}|<$1) in Au+Au collisions at $\sqrt{s_{\rm NN}}$ = 200\,GeV. The measurements are evaluated in different invariant mass regions with a focus on 0.30-0.76 ($\rho$-like), 0.76-0.80 ($\omega$-like), and 0.98-1.05 ($\phi$-like) GeV/$c^{2}$. The spectrum in the $\omega$-like and $\phi$-like regions can be well described by the hadronic cocktail simulation. In the $\rho$-like region, however, the vacuum $\rho$ spectral function cannot describe the shape of the dielectron excess. In this range, an enhancement of 1.77$\pm$0.11(stat.)$\pm$0.24(sys.)$\pm$0.33(cocktail) is determined with respect to the hadronic cocktail simulation that excludes the $\rho$ meson. The excess yield in the $\rho$-like region increases with the number of collision participants faster than the $\omega$ and $\phi$ yields. Theoretical models with broadened $\rho$ contributions through interactions with constituents in the hot QCD medium provide a consistent description of the dilepton mass spectra for the measurement presented here and the earlier data at the Super Proton Synchrotron energies.

Published
2013
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12. Suppression of Upsilon Production in d+Au and Au+Au Collisions at sqrt(s_NN) = 200 GeV

Author

Adamczyk, L., Adkins, J. K., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alekseev, I., Alford, J., Anson, C. D., Aparin, A., Arkhipkin, D., Aschenauer, E. C., Averichev, G. S., Banerjee, A., Beavis, D. R., Bellwied, R., Bhasin, A., Bhati, A. K., Bhattarai, P., Bichsel, H., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Borowski, W., Bouchet, J., Brandin, A. V., Brovko, S. G., Bültmann, S., Bunzarov, I., Burton, T. P., Butterworth, J., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Cendejas, R., Cervantes, M. C., Chaloupka, P., Chang, Z., Chattopadhyay, S., Chen, H. F., Chen, J. H., Chen, L., Cheng, J., Cherney, M., Chikanian, A., Christie, W., Chwastowski, J., Codrington, M. J. M., Contin, G., Cramer, J. G., Crawford, H. J., Cui, X., Das, S., Leyva, A. Davila, De Silva, L. C., Debbe, R. R., Dedovich, T. G., Deng, J., Derevschikov, A. A., de Souza, R. Derradi, Dhamija, S., di Ruzza, B., Didenko, L., Dilks, C., Ding, F., Djawotho, P., Dong, X., Drachenberg, J. L., Draper, J. E., Du, C. M., Dunkelberger, L. E., Dunlop, J. C., Efimov, L. G., Engelage, J., Engle, K. S., Eppley, G., Eun, L., Evdokimov, O., Fatemi, R., Fazio, S., Fedorisin, J., Filip, P., Finch, E., Fisyak, Y., Flores, C. E., Gagliardi, C. A., Gangadharan, D. R., Garand, D., Geurts, F., Gibson, A., Girard, M., Gliske, S., Greiner, L., Grosnick, D., Guo, Y., Gupta, A., Gupta, S., Guryn, W., Haag, B., Hajkova, O., Hamed, A., Han, L-X., Haque, R., Harris, J. W., Heppelmann, S., Hill, K., Hirsch, A., Hoffmann, G. W., Hofman, D. J., Horvat, S., Huang, B., Huang, H. Z., Huang, X., Huck, P., Humanic, T. J., Igo, G., Jacobs, W. W., Jang, H., Judd, E. G., Kabana, S., Kalinkin, D., Kang, K., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kesich, A., Khan, Z. H., Kikola, D. P., Kisel, I., Kisiel, A., Koetke, D. D., Kollegger, T., Konzer, J., Koralt, I., Kotchenda, L., Kravtsov, P., Krueger, K., Kulakov, I., Kumar, L., Kycia, R. A., Lamont, M. A. C., Landgraf, J. M., Landry, K. D., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., LeVine, M. J., Li, C., Li, W., Li, X., Li, Y., Li, Z. M., Lima, L. M., Lisa, M. A., Liu, F., Ljubicic, T., Llope, W. J., Lomnitz, M., Longacre, R. S., Luo, X., Ma, G. L., Ma, Y. G., Don, D. M. M. D. Madagodagettige, Mahapatra, D. P., Majka, R., Margetis, S., Markert, C., Masui, H., Matis, H. S., McDonald, D., McShane, T. S., Minaev, N. G., Mioduszewski, S., Mohanty, B., Mondal, M. M., Morozov, D. A., Munhoz, M. G., Mustafa, M. K., Nandi, B. K., Nasim, Md., Nayak, T. K., Nelson, J. M., Nigmatkulov, G., Nogach, L. V., Noh, S. Y., Novak, J., Nurushev, S. B., Odyniec, G., Ogawa, A., Oh, K., Ohlson, A., Okorokov, V., Oldag, E. W., Oliveira, R. A. N., Pachr, M., Page, B. S., Pal, S. K., Pan, Y. X., Pandit, Y., Panebratsev, Y., Pawlak, T., Pawlik, B., Pei, H., Perkins, C., Peryt, W., Peterson, A., Pile, P., Planinic, M., Pluta, J., Poljak, N., Porter, J., Poskanzer, A. M., Pruthi, N. K., Przybycien, M., Pujahari, P. R., Putschke, J., Qiu, H., Quintero, A., Ramachandran, S., Raniwala, R., Raniwala, S., Ray, R. L., Riley, C. K., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ross, J. F., Roy, A., Ruan, L., Rusnak, J., Sahoo, N. R., Sahu, P. K., Sakrejda, I., Salur, S., Sandweiss, J., Sangaline, E., Sarkar, A., Schambach, J., Scharenberg, R. P., Schmah, A. M., Schmidke, W. B., Schmitz, N., Seger, J., Seyboth, P., Shah, N., Shahaliev, E., Shanmuganathan, P. V., Shao, M., Sharma, B., Shen, W. Q., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Singaraju, R. N., Skoby, M. J., Smirnov, D., Smirnov, N., Solanki, D., Sorensen, P., deSouza, U. G., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Stevens, J. R., Stock, R., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Sumbera, M., Sun, X., Sun, X. M., Sun, Y., Sun, Z., Surrow, B., Svirida, D. N., Symons, T. J. M., de Toledo, A. Szanto, Szelezniak, M. A., Takahashi, J., Tang, A. H., Tang, Z., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Tlusty, D., Tokarev, M., Trentalange, S., Tribble, R. E., Tribedy, P., Trzeciak, B. A., Tsai, O. D., Turnau, J., Ullrich, T., Underwood, D. G., Van Buren, G., van Nieuwenhuizen, G., Vanfossen, Jr., J. A., Varma, R., Vasconcelos, G. M. S., Vasiliev, A. N., Vertesi, R., Videbæk, F., Viyogi, Y. P., Vokal, S., Vossen, A., Wada, M., Wang, F., Wang, G., Wang, H., Wang, J. S., Wang, X. L., Wang, Y., Webb, G., Webb, J. C., Westfall, G. D., Wieman, H., Wimsatt, G., Wissink, S. W., Witt, R., Wu, Y. F., Xiao, Z., Xie, W., Xin, K., Xu, H., Xu, J., Xu, N., Xu, Q. H., Xu, Y., Xu, Z., Yan, W., Yang, C., Yang, Y., Ye, Z., Yepes, P., Yi, L., Yip, K., Yoo, I-K., Yu, N., Zawisza, Y., Zbroszczyk, H., Zha, W., Zhang, J. B., Zhang, J. L., Zhang, S., Zhang, X. P., Zhang, Y., Zhang, Z. P., Zhao, F., Zhao, J., Zhong, C., Zhu, X., Zhu, Y. H., Zoulkarneeva, Y., and Zyzak, M.

Subjects
Nuclear Experiment
Abstract

We report measurements of Upsilon meson production in p+p, d+Au, and Au+Au collisions using the STAR detector at RHIC. We compare the Upsilon yield to the measured cross section in p+p collisions in order to quantify any modifications of the yield in cold nuclear matter using d+Au data and in hot nuclear matter using Au+Au data separated into three centrality classes. Our p+p measurement is based on three times the statistics of our previous result. We obtain a nuclear modification factor for Upsilon(1S+2S+3S) in the rapidity range |y|<1 in d+Au collisions of R_dAu = 0.79 +/- 0.24 (stat.) +/- 0.03 (sys.) +/- 0.10 (pp sys.). A comparison with models including shadowing and initial state parton energy loss indicates the presence of additional cold-nuclear matter suppression. Similarly, in the top 10% most-central Au+Au collisions, we measure a nuclear modification factor of R_AA=0.49 +/- 0.1 (stat.) +/- 0.02 (sys.) +/- 0.06 (pp sys.), which is a larger suppression factor than that seen in cold nuclear matter. Our results are consistent with complete suppression of excited-state Upsilon mesons in Au+Au collisions. The additional suppression in Au+Au is consistent with the level expected in model calculations that include the presence of a hot, deconfined Quark-Gluon Plasma. However, understanding the suppression seen in d+Au is still needed before any definitive statements about the nature of the suppression in Au+Au can be made., Comment: 13 pages, 7 figures

Published
2013
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13. Precision Measurement of the Longitudinal Double-Spin Asymmetry for Inclusive Jet Production in Polarized Proton Collisions at s=200 GeV

Author

Adamczyk, L, Adkins, JK, Agakishiev, G, Aggarwal, MM, Ahammed, Z, Alekseev, I, Alford, J, Anson, CD, Aparin, A, Arkhipkin, D, Aschenauer, EC, Averichev, GS, Banerjee, A, Beavis, DR, Bellwied, R, Bhasin, A, Bhati, AK, Bhattarai, P, Bichsel, H, Bielcik, J, Bielcikova, J, Bland, LC, Bordyuzhin, IG, Borowski, W, Bouchet, J, Brandin, AV, Brovko, SG, Bültmann, S, Bunzarov, I, Burton, TP, Butterworth, J, Caines, H, Calderón de la Barca Sánchez, M, Campbell, JM, Cebra, D, Cendejas, R, Cervantes, MC, Chaloupka, P, Chang, Z, Chattopadhyay, S, Chen, HF, Chen, JH, Chen, L, Cheng, J, Cherney, M, Chikanian, A, Christie, W, Chwastowski, J, Codrington, MJM, Contin, G, Cramer, JG, Crawford, HJ, Cudd, AB, Cui, X, Das, S, Davila Leyva, A, De Silva, LC, Debbe, RR, Dedovich, TG, Deng, J, Derevschikov, AA, Derradi de Souza, R, Dhamija, S, di Ruzza, B, Didenko, L, Dilks, C, Ding, F, Djawotho, P, Dong, X, Drachenberg, JL, Draper, JE, Du, CM, Dunkelberger, LE, Dunlop, JC, Efimov, LG, Engelage, J, Engle, KS, Eppley, G, Eun, L, Evdokimov, O, Eyser, O, Fatemi, R, Fazio, S, Fedorisin, J, Filip, P, Finch, E, Fisyak, Y, Flores, CE, Gagliardi, CA, Gangadharan, DR, Garand, D, Geurts, F, Gibson, A, Girard, M, Gliske, S, Greiner, L, Grosnick, D, Gunarathne, DS, Guo, Y, and Gupta, A

Subjects
STAR Collaboration, hep-ex, nucl-ex, Mathematical Sciences, Physical Sciences, Engineering, General Physics
Abstract

We report a new measurement of the midrapidity inclusive jet longitudinal double-spin asymmetry, A_{LL}, in polarized pp collisions at center-of-mass energy sqrt[s]=200  GeV. The STAR data place stringent constraints on polarized parton distribution functions extracted at next-to-leading order from global analyses of inclusive deep-inelastic scattering (DIS), semi-inclusive DIS, and RHIC pp data. The measured asymmetries provide evidence at the 3σ level for positive gluon polarization in the Bjorken-x region x>0.05.

Published
2015

14. Beam-energy-dependent two-pion interferometry and the freeze-out eccentricity of pions measured in heavy ion collisions at the STAR detector

Author

Adamczyk, L, Adkins, JK, Agakishiev, G, Aggarwal, MM, Ahammed, Z, Alekseev, I, Alford, J, Anson, CD, Aparin, A, Arkhipkin, D, Aschenauer, EC, Averichev, GS, Banerjee, A, Beavis, DR, Bellwied, R, Bhasin, A, Bhati, AK, Bhattarai, P, Bichsel, H, Bielcik, J, Bielcikova, J, Bland, LC, Bordyuzhin, IG, Borowski, W, Bouchet, J, Brandin, AV, Brovko, SG, Bültmann, S, Bunzarov, I, Burton, TP, Butterworth, J, Caines, H, Calderón De La Barca Sánchez, M, Cebra, D, Cendejas, R, Cervantes, MC, Chaloupka, P, Chang, Z, Chattopadhyay, S, Chen, HF, Chen, JH, Chen, L, Cheng, J, Cherney, M, Chikanian, A, Christie, W, Chwastowski, J, Codrington, MJM, Contin, G, Cramer, JG, Crawford, HJ, Cui, X, Das, S, Davila Leyva, A, De Silva, LC, Debbe, RR, Dedovich, TG, Deng, J, Derevschikov, AA, Derradi De Souza, R, Dhamija, S, Di Ruzza, B, Didenko, L, Dilks, C, Ding, F, Djawotho, P, Dong, X, Drachenberg, JL, Draper, JE, Du, CM, Dunkelberger, LE, Dunlop, JC, Efimov, LG, Engelage, J, Engle, KS, Eppley, G, Eun, L, Evdokimov, O, Eyser, O, Fatemi, R, Fazio, S, Fedorisin, J, Filip, P, Finch, E, Fisyak, Y, Flores, CE, Gagliardi, CA, Gangadharan, DR, Garand, D, Geurts, F, Gibson, A, Girard, M, Gliske, S, Greiner, L, Grosnick, D, Gunarathne, DS, Guo, Y, Gupta, A, Gupta, S, and Guryn, W

Subjects
nucl-ex, Nuclear & Particles Physics, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Atomic, Molecular, Nuclear, Particle and Plasma Physics
Abstract

We present results of analyses of two-pion interferometry in Au+Au collisions at sNN=7.7, 11.5, 19.6, 27, 39, 62.4, and 200 GeV measured in the STAR detector as part of the BNL Relativistic Heavy Ion Collider Beam Energy Scan program. The extracted correlation lengths (Hanbury-Brown-Twiss radii) are studied as a function of beam energy, azimuthal angle relative to the reaction plane, centrality, and transverse mass (mT) of the particles. The azimuthal analysis allows extraction of the eccentricity of the entire fireball at kinetic freeze-out. The energy dependence of this observable is expected to be sensitive to changes in the equation of state. A new global fit method is studied as an alternate method to directly measure the parameters in the azimuthal analysis. The eccentricity shows a monotonic decrease with beam energy that is qualitatively consistent with the trend from all model predictions and quantitatively consistent with a hadronic transport model.

Published
2015

15. Isolation of flow and nonflow correlations by two- and four-particle cumulant measurements of azimuthal harmonics in sNN=200GeV Au+Au collisions

Author

Abdelwahab, NM, Adamczyk, L, Adkins, JK, Agakishiev, G, Aggarwal, MM, Ahammed, Z, Alekseev, I, Alford, J, Anson, CD, Aparin, A, Arkhipkin, D, Aschenauer, EC, Averichev, GS, Banerjee, A, Beavis, DR, Bellwied, R, Bhasin, A, Bhati, AK, Bhattarai, P, Bielcik, J, Bielcikova, J, Bland, LC, Bordyuzhin, IG, Borowski, W, Bouchet, J, Brandin, AV, Brovko, SG, Bültmann, S, Bunzarov, I, Burton, TP, Butterworth, J, Caines, H, de la Barca Sánchez, CM, Campbell, JM, Cebra, D, Cendejas, R, Cervantes, MC, Chaloupka, P, Chang, Z, Chattopadhyay, S, Chen, HF, Chen, JH, Chen, L, Cheng, J, Cherney, M, Chikanian, A, Christie, W, Codrington, MJM, Contin, G, Cramer, JG, Crawford, HJ, Cui, X, Das, S, Davila Leyva, A, DeSilva, LC, Debbe, RR, Dedovich, TG, Deng, J, Derevschikov, AA, de Souza, RD, di Ruzza, B, Didenko, L, Dilks, C, Ding, F, Djawotho, P, Dong, X, Drachenberg, JL, Draper, JE, Du, CM, Dunkelberger, LE, Dunlop, JC, Efimov, LG, Engelage, J, Engle, KS, Eppley, G, Eun, L, Evdokimov, O, Eyser, O, Fatemi, R, Fazio, S, Fedorisin, J, Filip, P, Fisyak, Y, Flores, CE, Gagliardi, CA, Gangadharan, DR, Garand, D, Geurts, F, Gibson, A, Girard, M, Gliske, S, Greiner, L, Grosnick, D, Gunarathne, DS, Guo, Y, Gupta, A, Gupta, S, Guryn, W, Haag, B, and Hamed, A

Subjects
Heavy-ion, Flow, Nonflow, nucl-ex, Nuclear & Particles Physics, Mathematical Physics, Astronomical and Space Sciences, Atomic, Molecular, Nuclear, Particle and Plasma Physics
Abstract

A data-driven method was applied to Au+Au collisions at sNN=200GeV made with the STAR detector at RHIC to isolate pseudorapidity distance δη-dependent and δη-independent correlations by using two- and four-particle azimuthal cumulant measurements. We identified a δη-independent component of the correlation, which is dominated by anisotropic flow and flow fluctuations. It was also found to be independent of η within the measured range of pseudorapidity |η|0.7.

Published
2015

16. Isolation of flow and nonflow correlations by two- and four-particle cumulant measurements of azimuthal harmonics in sNN=200 GeV Au+Au collisions

Author

Collaboration, STAR, Abdelwahab, NM, Adamczyk, L, Adkins, JK, Agakishiev, G, Aggarwal, MM, Ahammed, Z, Alekseev, I, Alford, J, Anson, CD, Aparin, A, Arkhipkin, D, Aschenauer, EC, Averichev, GS, Banerjee, A, Beavis, DR, Bellwied, R, Bhasin, A, Bhati, AK, Bhattarai, P, Bielcik, J, Bielcikova, J, Bland, LC, Bordyuzhin, IG, Borowski, W, Bouchet, J, Brandin, AV, Brovko, SG, Bültmann, S, Bunzarov, I, Burton, TP, Butterworth, J, Caines, H, de la Barca Sánchez, M Calderón, Campbell, JM, Cebra, D, Cendejas, R, Cervantes, MC, Chaloupka, P, Chang, Z, Chattopadhyay, S, Chen, HF, Chen, JH, Chen, L, Cheng, J, Cherney, M, Chikanian, A, Christie, W, Codrington, MJM, Contin, G, Cramer, JG, Crawford, HJ, Cui, X, Das, S, Leyva, A Davila, De Silva, LC, Debbe, RR, Dedovich, TG, Deng, J, Derevschikov, AA, de Souza, R Derradi, di Ruzza, B, Didenko, L, Dilks, C, Ding, F, Djawotho, P, Dong, X, Drachenberg, JL, Draper, JE, Du, CM, Dunkelberger, LE, Dunlop, JC, Efimov, LG, Engelage, J, Engle, KS, Eppley, G, Eun, L, Evdokimov, O, Eyser, O, Fatemi, R, Fazio, S, Fedorisin, J, Filip, P, Fisyak, Y, Flores, CE, Gagliardi, CA, Gangadharan, DR, Garand, D, Geurts, F, Gibson, A, Girard, M, Gliske, S, Greiner, L, Grosnick, D, Gunarathne, DS, Guo, Y, Gupta, A, Gupta, S, Guryn, W, and Haag, B

Subjects
Heavy-ion, Flow, Nonflow, nucl-ex, Mathematical Physics, Astronomical and Space Sciences, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Nuclear & Particles Physics
Abstract

A data-driven method was applied to Au+Au collisions at sNN=200GeV made with the STAR detector at RHIC to isolate pseudorapidity distance δη-dependent and δη-independent correlations by using two- and four-particle azimuthal cumulant measurements. We identified a δη-independent component of the correlation, which is dominated by anisotropic flow and flow fluctuations. It was also found to be independent of η within the measured range of pseudorapidity |η|0.7.

Published
2015

17. Corrigendum to “Suppression of ϒ production in d+Au and Au+Au collisions at sNN=200 GeV” [Phys. Lett. B 735 (2014) 127–137]

Author

Collaboration, STAR, Adamczyk, L, Adkins, JK, Agakishiev, G, Aggarwal, MM, Ahammed, Z, Alekseev, I, Alford, J, Anson, CD, Aparin, A, Arkhipkin, D, Aschenauer, EC, Averichev, GS, Balewski, J, Banerjee, A, Barnovska, Z, Beavis, DR, Bellwied, R, Bhasin, A, Bhati, AK, Bhattarai, P, Bichsel, H, Bielcik, J, Bielcikova, J, Bland, LC, Bordyuzhin, IG, Borowski, W, Bouchet, J, Brandin, AV, Brovko, SG, Bültmann, S, Bunzarov, I, Burton, TP, Butterworth, J, Caines, H, de la Barca Sánchez, M Calderón, Cebra, D, Cendejas, R, Cervantes, MC, Chaloupka, P, Chang, Z, Chattopadhyay, S, Chen, HF, Chen, JH, Chen, L, Cheng, J, Cherney, M, Chikanian, A, Christie, W, Chwastowski, J, Codrington, MJM, Corliss, R, Cramer, JG, Crawford, HJ, Cui, X, Das, S, Leyva, A Davila, De Silva, LC, Debbe, RR, Dedovich, TG, Deng, J, Derevschikov, AA, de Souza, R Derradi, Dhamija, S, di Ruzza, B, Didenko, L, Dilks, C, Ding, F, Djawotho, P, Dong, X, Drachenberg, JL, Draper, JE, Du, CM, Dunkelberger, LE, Dunlop, JC, Efimov, LG, Engelage, J, Engle, KS, Eppley, G, Eun, L, Evdokimov, O, Fatemi, R, Fazio, S, Fedorisin, J, Filip, P, Finch, E, Fisyak, Y, Flores, CE, Gagliardi, CA, Gangadharan, DR, Garand, D, Geurts, F, Gibson, A, Girard, M, Gliske, S, Grosnick, D, Guo, Y, Gupta, A, Gupta, S, and Guryn, W

Subjects
Mathematical Physics, Astronomical and Space Sciences, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Nuclear & Particles Physics
Published
2015

18. Charged-to-neutral correlation at forward rapidity in Au + Au collisions at sNN =200 GeV

Author

Adamczyk, L, Adkins, JK, Agakishiev, G, Aggarwal, MM, Ahammed, Z, Alekseev, I, Alford, J, Anson, CD, Aparin, A, Arkhipkin, D, Aschenauer, EC, Averichev, GS, Banerjee, A, Beavis, DR, Bellwied, R, Bhasin, A, Bhati, AK, Bhattarai, P, Bichsel, H, Bielcik, J, Bielcikova, J, Bland, LC, Bordyuzhin, IG, Borowski, W, Bouchet, J, Brandin, AV, Brovko, SG, Bültmann, S, Bunzarov, I, Burton, TP, Butterworth, J, Caines, H, De La Barca Sánchez, MC, Campbell, JM, Cebra, D, Cendejas, R, Cervantes, MC, Chaloupka, P, Chang, Z, Chattopadhyay, S, Chen, HF, Chen, JH, Chen, L, Cheng, J, Cherney, M, Chikanian, A, Christie, W, Chwastowski, J, Codrington, MJM, Contin, G, Cramer, JG, Crawford, HJ, Cui, X, Das, S, Davila Leyva, A, De Silva, LC, Debbe, RR, Dedovich, TG, Deng, J, Derevschikov, AA, Derradi De Souza, R, Di Ruzza, B, Didenko, L, Dilks, C, Ding, F, Djawotho, P, Dong, X, Drachenberg, JL, Draper, JE, Du, CM, Dunkelberger, LE, Dunlop, JC, Efimov, LG, Engelage, J, Engle, KS, Eppley, G, Eun, L, Evdokimov, O, Eyser, O, Fatemi, R, Fazio, S, Fedorisin, J, Filip, P, Fisyak, Y, Flores, CE, Gagliardi, CA, Gangadharan, DR, Garand, D, Geurts, F, Gibson, A, Girard, M, Gliske, S, Greiner, L, Grosnick, D, Gunarathne, DS, Guo, Y, Gupta, A, Gupta, S, Guryn, W, and Haag, B

Subjects
nucl-ex, hep-ex, Nuclear & Particles Physics, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Atomic, Molecular, Nuclear, Particle and Plasma Physics
Abstract

Event-by-event fluctuations of the multiplicities of inclusive charged particles and photons at forward rapidity in Au+Au collisions at sNN=200 GeV have been studied. The dominant contribution to such fluctuations is expected to come from correlated production of charged and neutral pions. We search for evidence of dynamical fluctuations of different physical origins. Observables constructed out of moments of multiplicities are used as measures of fluctuations. Mixed events and model calculations are used as base lines. Results are compared to the dynamical net-charge fluctuations measured in the same acceptance. A nonzero statistically significant signal of dynamical fluctuations is observed in excess to the model prediction when charged particles and photons are measured in the same acceptance. We find that, unlike dynamical net-charge fluctuation, charge-neutral fluctuation is not dominated by correlation owing to particle decay. Results are compared to the expectations based on the generic production mechanism of pions owing to isospin symmetry, for which no significant (

Published
2015

19. Charged-to-neutral correlation at forward rapidity in Au + Au collisions at sNN=200 GeV

Author

Adamczyk, L, Adkins, JK, Agakishiev, G, Aggarwal, MM, Ahammed, Z, Alekseev, I, Alford, J, Anson, CD, Aparin, A, Arkhipkin, D, Aschenauer, EC, Averichev, GS, Banerjee, A, Beavis, DR, Bellwied, R, Bhasin, A, Bhati, AK, Bhattarai, P, Bichsel, H, Bielcik, J, Bielcikova, J, Bland, LC, Bordyuzhin, IG, Borowski, W, Bouchet, J, Brandin, AV, Brovko, SG, Bültmann, S, Bunzarov, I, Burton, TP, Butterworth, J, Caines, H, de la Barca Sánchez, M Calderón, Campbell, JM, Cebra, D, Cendejas, R, Cervantes, MC, Chaloupka, P, Chang, Z, Chattopadhyay, S, Chen, HF, Chen, JH, Chen, L, Cheng, J, Cherney, M, Chikanian, A, Christie, W, Chwastowski, J, Codrington, MJM, Contin, G, Cramer, JG, Crawford, HJ, Cui, X, Das, S, Leyva, A Davila, De Silva, LC, Debbe, RR, Dedovich, TG, Deng, J, Derevschikov, AA, de Souza, R Derradi, di Ruzza, B, Didenko, L, Dilks, C, Ding, F, Djawotho, P, Dong, X, Drachenberg, JL, Draper, JE, Du, CM, Dunkelberger, LE, Dunlop, JC, Efimov, LG, Engelage, J, Engle, KS, Eppley, G, Eun, L, Evdokimov, O, Eyser, O, Fatemi, R, Fazio, S, Fedorisin, J, Filip, P, Fisyak, Y, Flores, CE, Gagliardi, CA, Gangadharan, DR, Garand, D, Geurts, F, Gibson, A, Girard, M, Gliske, S, Greiner, L, Grosnick, D, Gunarathne, DS, Guo, Y, Gupta, A, Gupta, S, Guryn, W, and Haag, B

Subjects
nucl-ex, hep-ex, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Nuclear & Particles Physics
Abstract

Event-by-event fluctuations of the multiplicities of inclusive charged particles and photons at forward rapidity in Au+Au collisions at sNN=200 GeV have been studied. The dominant contribution to such fluctuations is expected to come from correlated production of charged and neutral pions. We search for evidence of dynamical fluctuations of different physical origins. Observables constructed out of moments of multiplicities are used as measures of fluctuations. Mixed events and model calculations are used as base lines. Results are compared to the dynamical net-charge fluctuations measured in the same acceptance. A nonzero statistically significant signal of dynamical fluctuations is observed in excess to the model prediction when charged particles and photons are measured in the same acceptance. We find that, unlike dynamical net-charge fluctuation, charge-neutral fluctuation is not dominated by correlation owing to particle decay. Results are compared to the expectations based on the generic production mechanism of pions owing to isospin symmetry, for which no significant (

Published
2015

20. ΛΛ Correlation Function in Au+Au Collisions at sNN=200 GeV

Author

Adamczyk, L, Adkins, JK, Agakishiev, G, Aggarwal, MM, Ahammed, Z, Alekseev, I, Alford, J, Anson, CD, Aparin, A, Arkhipkin, D, Aschenauer, EC, Averichev, GS, Banerjee, A, Beavis, DR, Bellwied, R, Bhasin, A, Bhati, AK, Bhattarai, P, Bichsel, H, Bielcik, J, Bielcikova, J, Bland, LC, Bordyuzhin, IG, Borowski, W, Bouchet, J, Brandin, AV, Brovko, SG, Bültmann, S, Bunzarov, I, Burton, TP, Butterworth, J, Caines, H, Calderón de la Barca Sánchez, M, Campbell, JM, Cebra, D, Cendejas, R, Cervantes, MC, Chaloupka, P, Chang, Z, Chattopadhyay, S, Chen, HF, Chen, JH, Chen, L, Cheng, J, Cherney, M, Chikanian, A, Christie, W, Chwastowski, J, Codrington, MJM, Contin, G, Cramer, JG, Crawford, HJ, Cui, X, Das, S, Davila Leyva, A, De Silva, LC, Debbe, RR, Dedovich, TG, Deng, J, Derevschikov, AA, Derradi de Souza, R, di Ruzza, B, Didenko, L, Dilks, C, Ding, F, Djawotho, P, Dong, X, Drachenberg, JL, Draper, JE, Du, CM, Dunkelberger, LE, Dunlop, JC, Efimov, LG, Engelage, J, Engle, KS, Eppley, G, Eun, L, Evdokimov, O, Eyser, O, Fatemi, R, Fazio, S, Fedorisin, J, Filip, P, Fisyak, Y, Flores, CE, Gagliardi, CA, Gangadharan, DR, Garand, D, Geurts, F, Gibson, A, Girard, M, Gliske, S, Greiner, L, Grosnick, D, Gunarathne, DS, Guo, Y, Gupta, A, Gupta, S, Guryn, W, and Haag, B

Subjects
(STAR Collaboration), nucl-ex, Mathematical Sciences, Physical Sciences, Engineering, General Physics
Abstract

We present ΛΛ correlation measurements in heavy-ion collisions for Au+Au collisions at sqrt[s_{NN}]=200  GeV using the STAR experiment at the Relativistic Heavy-Ion Collider. The Lednický-Lyuboshitz analytical model has been used to fit the data to obtain a source size, a scattering length and an effective range. Implications of the measurement of the ΛΛ correlation function and interaction parameters for dihyperon searches are discussed.

Published
2015

21. ΛΛ Correlation function in Au+Au collisions at √[S(NN)]=200  GeV.

Author

Adamczyk, L, Adkins, JK, Agakishiev, G, Aggarwal, MM, Ahammed, Z, Alekseev, I, Alford, J, Anson, CD, Aparin, A, Arkhipkin, D, Aschenauer, EC, Averichev, GS, Banerjee, A, Beavis, DR, Bellwied, R, Bhasin, A, Bhati, AK, Bhattarai, P, Bichsel, H, Bielcik, J, Bielcikova, J, Bland, LC, Bordyuzhin, IG, Borowski, W, Bouchet, J, Brandin, AV, Brovko, SG, Bültmann, S, Bunzarov, I, Burton, TP, Butterworth, J, Caines, H, Calderón de la Barca Sánchez, M, Campbell, JM, Cebra, D, Cendejas, R, Cervantes, MC, Chaloupka, P, Chang, Z, Chattopadhyay, S, Chen, HF, Chen, JH, Chen, L, Cheng, J, Cherney, M, Chikanian, A, Christie, W, Chwastowski, J, Codrington, MJM, Contin, G, Cramer, JG, Crawford, HJ, Cui, X, Das, S, Davila Leyva, A, De Silva, LC, Debbe, RR, Dedovich, TG, Deng, J, Derevschikov, AA, Derradi de Souza, R, di Ruzza, B, Didenko, L, Dilks, C, Ding, F, Djawotho, P, Dong, X, Drachenberg, JL, Draper, JE, Du, CM, Dunkelberger, LE, Dunlop, JC, Efimov, LG, Engelage, J, Engle, KS, Eppley, G, Eun, L, Evdokimov, O, Eyser, O, Fatemi, R, Fazio, S, Fedorisin, J, Filip, P, Fisyak, Y, Flores, CE, Gagliardi, CA, Gangadharan, DR, Garand, D, Geurts, F, Gibson, A, Girard, M, Gliske, S, Greiner, L, Grosnick, D, Gunarathne, DS, Guo, Y, Gupta, A, Gupta, S, Guryn, W, and Haag, B

Subjects
(STAR Collaboration), nucl-ex, General Physics, Mathematical Sciences, Physical Sciences, Engineering
Abstract

We present ΛΛ correlation measurements in heavy-ion collisions for Au+Au collisions at sqrt[s_{NN}]=200  GeV using the STAR experiment at the Relativistic Heavy-Ion Collider. The Lednický-Lyuboshitz analytical model has been used to fit the data to obtain a source size, a scattering length and an effective range. Implications of the measurement of the ΛΛ correlation function and interaction parameters for dihyperon searches are discussed.

Published
2015

22. Corrigendum to "Suppression of Υ production in d + Au and Au + Au collisions at √sNN = 200 GeV" [Phys. Lett. B 735 (2014) 127-137]

Author

Adamczyk, L, Adkins, JK, Agakishiev, G, Aggarwal, MM, Ahammed, Z, Alekseev, I, Alford, J, Anson, CD, Aparin, A, Arkhipkin, D, Aschenauer, EC, Averichev, GS, Balewski, J, Banerjee, A, Barnovska, Z, Beavis, DR, Bellwied, R, Bhasin, A, Bhati, AK, Bhattarai, P, Bichsel, H, Bielcik, J, Bielcikova, J, Bland, LC, Bordyuzhin, IG, Borowski, W, Bouchet, J, Brandin, AV, Brovko, SG, Bültmann, S, Bunzarov, I, Burton, TP, Butterworth, J, Caines, H, Calderon De la Barca Sánchez, M, Cebra, D, Cendejas, R, Cervantes, MC, Chaloupka, P, Chang, Z, Chattopadhyay, S, Chen, HF, Chen, JH, Chen, L, Cheng, J, Cherney, M, Chikanian, A, Christie, W, Chwastowski, J, Codrington, MJM, Corliss, R, Cramer, JG, Crawford, HJ, Cui, X, Das, S, Davila Leyva, A, De Silva, LC, Debbe, RR, Dedovich, TG, Deng, J, Derevschikov, AA, Derradide Souza, R, Dhamija, S, Di Ruzza, B, Didenko, L, Dilks, C, Ding, F, Djawotho, P, Dong, X, Drachenberg, JL, Draper, JE, Du, CM, Dunkelberger, LE, Dunlop, JC, Efimov, LG, Engelage, J, Engle, KS, Eppley, G, Eun, L, Evdokimov, O, Fatemi, R, Fazio, S, Fedorisin, J, Filip, P, Finch, E, Fisyak, Y, Flores, CE, Gagliardi, CA, Gangadharan, DR, Garand, D, Geurts, F, Gibson, A, Girard, M, Gliske, S, Grosnick, D, Guo, Y, Gupta, A, Gupta, S, Guryn, W, and Haag, B

Subjects
Nuclear & Particles Physics, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Astronomical and Space Sciences, Mathematical Physics, Atomic, Molecular, Nuclear, Particle and Plasma Physics
Published
2015

23. $J/\psi$ polarization in p+p collisions at $\sqrt{s}$ = 200 GeV in STAR

Author

STAR Collaboration, Adamczyk, L., Adkins, J. K., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alekseev, I., Alford, J., Anson, C. D., Aparin, A., Arkhipkin, D., Aschenauer, E. C., Averichev, G. S., Balewski, J., Banerjee, A., Barnovska, Z., Beavis, D. R., Bellwied, R., Bhasin, A., Bhati, A. K., Bhattarai, P., Bichsel, H., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Borowski, W., Bouchet, J., Brandin, A. V., Brovko, S. G., Bültmann, S., Bunzarov, I., Burton, T. P., Butterworth, J., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Cendejas, R., Cervantes, M. C., Chaloupka, P., Chang, Z., Chattopadhyay, S., Chen, H. F., Chen, J. H., Chen, L., Cheng, J., Cherney, M., Chikanian, A., Christie, W., Chwastowski, J., Codrington, M. J. M., Corliss, R., Cramer, J. G., Crawford, H. J., Cui, X., Das, S., Leyva, A. Davila, De Silva, L. C., Debbe, R. R., Dedovich, T. G., Deng, J., Derevschikov, A. A., de Souza, R. Derradi, Dhamija, S., di Ruzza, B., Didenko, L., Dilks, C., Ding, F., Djawotho, P., Dong, X., Drachenberg, J. L., Draper, J. E., Du, C. M., Dunkelberger, L. E., Dunlop, J. C., Efimov, L. G., Engelage, J., Engle, K. S., Eppley, G., Eun, L., Evdokimov, O., Fatemi, R., Fazio, S., Fedorisin, J., Filip, P., Finch, E., Fisyak, Y., Flores, C. E., Gagliardi, C. A., Gangadharan, D. R., Garand, D., Geurts, F., Gibson, A., Girard, M., Gliske, S., Grosnick, D., Guo, Y., Gupta, A., Gupta, S., Guryn, W., Haag, B., Hajkova, O., Hamed, A., Han, L-X., Haque, R., Harris, J. W., Hays-Wehle, J. P., Heppelmann, S., Hirsch, A., Hoffmann, G. W., Hofman, D. J., Horvat, S., Huang, B., Huang, H. Z., Huang, X., Huck, P., Humanic, T. J., Igo, G., Jacobs, W. W., Jang, H., Judd, E. G., Kabana, S., Kalinkin, D., Kang, K., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kesich, A., Khan, Z. H., Kikola, D. P., Kisel, I., Kisiel, A., Koetke, D. D., Kollegger, T., Konzer, J., Koralt, I., Korsch, W., Kotchenda, L., Kravtsov, P., Krueger, K., Kulakov, I., Kumar, L., Kycia, R. A., Lamont, M. A. C., Landgraf, J. M., Landry, K. D., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Leight, W., LeVine, M. J., Li, C., Li, W., Li, X., Li, Y., Li, Z. M., Lima, L. M., Lisa, M. A., Liu, F., Ljubicic, T., Llope, W. J., Longacre, R. S., Luo, X., Ma, G. L., Ma, Y. G., Don, D. M. M. D. Madagodagettige, Mahapatra, D. P., Majka, R., Margetis, S., Markert, C., Masui, H., Matis, H. S., McDonald, D., McShane, T. S., Minaev, N. G., Mioduszewski, S., Mohanty, B., Mondal, M. M., Morozov, D. A., Munhoz, M. G., Mustafa, M. K., Nandi, B. K., Nasim, Md., Nayak, T. K., Nelson, J. M., Nogach, L. V., Noh, S. Y., Novak, J., Nurushev, S. B., Odyniec, G., Ogawa, A., Oh, K., Ohlson, A., Okorokov, V., Oldag, E. W., Oliveira, R. A. N., Pachr, M., Page, B. S., Pal, S. K., Pan, Y. X., Pandit, Y., Panebratsev, Y., Pawlak, T., Pawlik, B., Pei, H., Perkins, C., Peryt, W., Pile, P., Planinic, M., Pluta, J., Plyku, D., Poljak, N., Porter, J., Poskanzer, A. M., Pruthi, N. K., Przybycien, M., Pujahari, P. R., Qiu, H., Quintero, A., Ramachandran, S., Raniwala, R., Raniwala, S., Ray, R. L., Riley, C. K., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ross, J. F., Roy, A., Ruan, L., Rusnak, J., Sahoo, N. R., Sahu, P. K., Sakrejda, I., Salur, S., Sandacz, A., Sandweiss, J., Sangaline, E., Sarkar, A., Schambach, J., Scharenberg, R. P., Schmah, A. M., Schmidke, W. B., Schmitz, N., Seger, J., Seyboth, P., Shah, N., Shahaliev, E., Shanmuganathan, P. V., Shao, M., Sharma, B., Shen, W. Q., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Singaraju, R. N., Skoby, M. J., Smirnov, D., Smirnov, N., Solanki, D., Sorensen, P., deSouza, U. G., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Stevens, J. R., Stock, R., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Sumbera, M., Sun, X., Sun, X. M., Sun, Y., Sun, Z., Surrow, B., Svirida, D. N., Symons, T. J. M., de Toledo, A. Szanto, Takahashi, J., Tang, A. H., Tang, Z., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Tlusty, D., Tokarev, M., Trentalange, S., Tribble, R. E., Tribedy, P., Trzeciak, B. A., Tsai, O. D., Turnau, J., Ullrich, T., Underwood, D. G., Van Buren, G., van Nieuwenhuizen, G., Vanfossen, Jr., J. A., Varma, R., Vasconcelos, G. M. S., Vasiliev, A. N., Vertesi, R., Videbæk, F., Viyogi, Y. P., Vokal, S., Vossen, A., Wada, M., Walker, M., Wang, F., Wang, G., Wang, H., Wang, J. S., Wang, X. L., Wang, Y., Webb, G., Webb, J. C., Westfall, G. D., Wieman, H., Wissink, S. W., Witt, R., Wu, Y. F., Xiao, Z., Xie, W., Xin, K., Xu, H., Xu, N., Xu, Q. H., Xu, Y., Xu, Z., Yan, W., Yang, C., Yang, Y., Ye, Z., Yepes, P., Yi, L., Yip, K., Yoo, I-K., Zawisza, Y., Zbroszczyk, H., Zha, W., Zhang, J. B., Zhang, J. L., Zhang, S., Zhang, X. P., Zhang, Y., Zhang, Z. P., Zhao, F., Zhao, J., Zhong, C., Zhu, X., Zhu, Y. H., Zoulkarneeva, Y., and Zyzak, M.

Subjects
Nuclear Experiment
Abstract

We report on a polarization measurement of inclusive $J/\psi$ mesons in the di-electron decay channel at mid-rapidity at 2 $

Published
2013
Full Text
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24. $J/\psi$ production at low $p_T$ in Au+Au and Cu+Cu collisions at $\sqrt{s_{_{NN}}}$ = 200 GeV at STAR

Author

STAR Collaboration, Adamczyk, L., Adkins, J. K., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alekseev, I., Alford, J., Anson, C. D., Aparin, A., Arkhipkin, D., Aschenauer, E. C., Averichev, G. S., Balewski, J., Banerjee, A., Barnovska, Z., Beavis, D. R., Bellwied, R., Bhasin, A., Bhati, A. K., Bhattarai, P., Bichsel, H., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Borowski, W., Bouchet, J., Brandin, A. V., Brovko, S. G., Bültmann, S., Bunzarov, I., Burton, T. P., Butterworth, J., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Cendejas, R., Cervantes, M. C., Chaloupka, P., Chang, Z., Chattopadhyay, S., Chen, H. F., Chen, J. H., Chen, L., Cheng, J., Cherney, M., Chikanian, A., Christie, W., Chwastowski, J., Codrington, M. J. M., Corliss, R., Cramer, J. G., Crawford, H. J., Cui, X., Das, S., Leyva, A. Davila, De Silva, L. C., Debbe, R. R., Dedovich, T. G., Deng, J., Derevschikov, A. A., de Souza, R. Derradi, Dhamija, S., di Ruzza, B., Didenko, L., Dilks, C., Ding, F., Djawotho, P., Dong, X., Drachenberg, J. L., Draper, J. E., Du, C. M., Dunkelberger, L. E., Dunlop, J. C., Efimov, L. G., Engelage, J., Engle, K. S., Eppley, G., Eun, L., Evdokimov, O., Fatemi, R., Fazio, S., Fedorisin, J., Filip, P., Finch, E., Fisyak, Y., Flores, C. E., Gagliardi, C. A., Gangadharan, D. R., Garand, D., Geurts, F., Gibson, A., Girard, M., Gliske, S., Grosnick, D., Guo, Y., Gupta, A., Gupta, S., Guryn, W., Haag, B., Hajkova, O., Hamed, A., Han, L-X., Haque, R., Harris, J. W., Hays-Wehle, J. P., Heppelmann, S., Hirsch, A., Hoffmann, G. W., Hofman, D. J., Horvat, S., Huang, B., Huang, H. Z., Huck, P., Humanic, T. J., Igo, G., Jacobs, W. W., Jang, H., Judd, E. G., Kabana, S., Kalinkin, D., Kang, K., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kesich, A., Khan, Z. H., Kikola, D. P., Kisel, I., Kisiel, A., Koetke, D. D., Kollegger, T., Konzer, J., Koralt, I., Korsch, W., Kotchenda, L., Kravtsov, P., Krueger, K., Kulakov, I., Kumar, L., Kycia, R. A., Lamont, M. A. C., Landgraf, J. M., Landry, K. D., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Leight, W., LeVine, M. J., Li, C., Li, W., Li, X., Li, Y., Li, Z. M., Lima, L. M., Lisa, M. A., Liu, F., Ljubicic, T., Llope, W. J., Longacre, R. S., Luo, X., Ma, G. L., Ma, Y. G., Don, D. M. M. D. Madagodagettige, Mahapatra, D. P., Majka, R., Margetis, S., Markert, C., Masui, H., Matis, H. S., McDonald, D., McShane, T. S., Minaev, N. G., Mioduszewski, S., Mohanty, B., Mondal, M. M., Morozov, D. A., Munhoz, M. G., Mustafa, M. K., Nandi, B. K., Nasim, Md., Nayak, T. K., Nelson, J. M., Nogach, L. V., Noh, S. Y., Novak, J., Nurushev, S. B., Odyniec, G., Ogawa, A., Oh, K., Ohlson, A., Okorokov, V., Oldag, E. W., Oliveira, R. A. N., Pachr, M., Page, B. S., Pal, S. K., Pan, Y. X., Pandit, Y., Panebratsev, Y., Pawlak, T., Pawlik, B., Pei, H., Perkins, C., Peryt, W., Pile, P., Planinic, M., Pluta, J., Plyku, D., Poljak, N., Porter, J., Poskanzer, A. M., Pruthi, N. K., Przybycien, M., Pujahari, P. R., Qiu, H., Quintero, A., Ramachandran, S., Raniwala, R., Raniwala, S., Ray, R. L., Riley, C. K., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ross, J. F., Roy, A., Ruan, L., Rusnak, J., Sahoo, N. R., Sahu, P. K., Sakrejda, I., Salur, S., Sandacz, A., Sandweiss, J., Sangaline, E., Sarkar, A., Schambach, J., Scharenberg, R. P., Schmah, A. M., Schmidke, W. B., Schmitz, N., Seger, J., Seyboth, P., Shah, N., Shahaliev, E., Shanmuganathan, P. V., Shao, M., Sharma, B., Shen, W. Q., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Singaraju, R. N., Skoby, M. J., Smirnov, D., Smirnov, N., Solanki, D., Sorensen, P., deSouza, U. G., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Stevens, J. R., Stock, R., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Sumbera, M., Sun, X., Sun, X. M., Sun, Y., Sun, Z., Surrow, B., Svirida, D. N., Symons, T. J. M., de Toledo, A. Szanto, Takahashi, J., Tang, A. H., Tang, Z., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Tlusty, D., Tokarev, M., Trentalange, S., Tribble, R. E., Tribedy, P., Trzeciak, B. A., Tsai, O. D., Turnau, J., Ullrich, T., Underwood, D. G., Van Buren, G., van Nieuwenhuizen, G., Vanfossen, Jr., J. A., Varma, R., Vasconcelos, G. M. S., Vasiliev, A. N., Vertesi, R., Videbæk, F., Viyogi, Y. P., Vokal, S., Vossen, A., Wada, M., Walker, M., Wang, F., Wang, G., Wang, H., Wang, J. S., Wang, X. L., Wang, Y., Webb, G., Webb, J. C., Westfall, G. D., Wieman, H., Wissink, S. W., Witt, R., Wu, Y. F., Xiao, Z., Xie, W., Xin, K., Xu, H., Xu, N., Xu, Q. H., Xu, Y., Xu, Z., Yan, W., Yang, C., Yang, Y., Ye, Z., Yepes, P., Yi, L., Yip, K., Yoo, I-K., Zawisza, Y., Zbroszczyk, H., Zha, W., Zhang, Zhang, J. B., Zhang, S., Zhang, X. P., Zhang, Y., Zhang, Z. P., Zhao, F., Zhao, J., Zhong, C., Zhu, X., Zhu, Y. H., Zoulkarneeva, Y., and Zyzak, M.

Subjects
Nuclear Experiment
Abstract

The $\jpsi$ $\pt$ spectrum and nuclear modification factor ($\raa$) are reported for $\pt < 5 \ \gevc$ and $|y|<1$ from 0\% to 60\% central Au+Au and Cu+Cu collisions at $\snn = 200 \ \gev$ at STAR. A significant suppression of $\pt$-integrated $\jpsi$ production is observed in central Au+Au events. The Cu+Cu data are consistent with no suppression, although the precision is limited by the available statistics. $\raa$ in Au+Au collisions exhibits a strong suppression at low transverse momentum and gradually increases with $\pt$. The data are compared to high-$\pt$ STAR results and previously published BNL Relativistic Heavy Ion Collider results. Comparing with model calculations, it is found that the invariant yields at low $\pt$ are significantly above hydrodynamic flow predictions but are consistent with models that include color screening and regeneration., Comment: 14 pages, 13 figures. Accepted by Phys. Rev. C

Published
2013
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25. Energy Dependence of Moments of Net-proton Multiplicity Distributions at RHIC

Author

STAR Collaboration, Adamczyk, L., Adkins, J. K., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alekseev, I., Alford, J., Anson, C. D., Aparin, A., Arkhipkin, D., Aschenauer, E. C., Averichev, G. S., Balewski, J., Banerjee, A., Barnovska, Z., Beavis, D. R., Bellwied, R., Bhasin, A., Bhati, A. K., Bhattarai, P., Bichsel, H., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Borowski, W., Bouchet, J., Brandin, A. V., Brovko, S. G., Bültmann, S., Bunzarov, I., Burton, T. P., Butterworth, J., Caines, H., Sánchez, M. Calderóndela Barca, Cebra, D., Cendejas, R., Cervantes, M. C., Chaloupka, P., Chang, Z., Chattopadhyay, S., Chen, H. F., Chen, J. H., Chen, L., Cheng, J., Cherney, M., Chikanian, A., Christie, W., Chwastowski, J., Codrington, M. J. M., Corliss, R., Cramer, J. G., Crawford, H. J., Cui, X., Das, S., Leyva, A. Davila, De Silva, L. C., Debbe, R. R., Dedovich, T. G., Deng, J., Derevschikov, A. A., de Souza, R. Derradi, Dhamija, S., di Ruzza, B., Didenko, L., Dilks, C., Ding, F., Djawotho, P., Dong, X., Drachenberg, J. L., Draper, J. E., Du, C. M., Dunkelberger, L. E., Dunlop, J. C., Efimov, L. G., Engelage, J., Engle, K. S., Eppley, G., Eun, L., Evdokimov, O., Fatemi, R., Fazio, S., Fedorisin, J., Filip, P., Finch, E., Fisyak, Y., Flores, C. E., Gagliardi, C. A., Gangadharan, D. R., Garand, D., Geurts, F., Gibson, A., Girard, M., Gliske, S., Grosnick, D., Guo, Y., Gupta, A., Gupta, S., Guryn, W., Haag, B., Hajkova, O., Hamed, A., Han, L-X., Haque, R., Harris, J. W., Hays-Wehle, J. P., Heppelmann, S., Hirsch, A., Hoffmann, G. W., Hofman, D. J., Horvat, S., Huang, B., Huang, H. Z., Huck, P., Humanic, T. J., Igo, G., Jacobs, W. W., Jang, H., Judd, E. G., Kabana, S., Kalinkin, D., Kang, K., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kesich, A., Khan, Z. H., Kikola, D. P., Kisel, I., Kisiel, A., Koetke, D. D., Kollegger, T., Konzer, J., Koralt, I., Korsch, W., Kotchenda, L., Kravtsov, P., Krueger, K., Kulakov, I., Kumar, L., Kycia, R. A., Lamont, M. A. C., Landgraf, J. M., Landry, K. D., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Leight, W., LeVine, M. J., Li, C., Li, W., Li, X., Li, Y., Li, Z. M., Lima, L. M., Lisa, M. A., Liu, F., Ljubicic, T., Llope, W. J., Longacre, R. S., Luo, X., Ma, G. L., Ma, Y. G., Don, D. M. M. D. Madagodagettige, Mahapatra, D. P., Majka, R., Margetis, S., Markert, C., Masui, H., Matis, H. S., McDonald, D., McShane, T. S., Minaev, N. G., Mioduszewski, S., Mohanty, B., Mondal, M. M., Morozov, D. A., Munhoz, M. G., Mustafa, M. K., Nandi, B. K., Nasim, Md., Nayak, T. K., Nelson, J. M., Nogach, L. V., Noh, S. Y., Novak, J., Nurushev, S. B., Odyniec, G., Ogawa, A., Oh, K., Ohlson, A., Okorokov, V., Oldag, E. W., Oliveira, R. A. N., Pachr, M., Page, B. S., Pal, S. K., Pan, Y. X., Pandit, Y., Panebratsev, Y., Pawlak, T., Pawlik, B., Pei, H., Perkins, C., Peryt, W., Peterson, A., Pile, P., Planinic, M., Pluta, J., Plyku, D., Poljak, N., Porter, J., Poskanzer, A. M., Pruthi, N. K., Przybycien, M., Pujahari, P. R., Qiu, H., Quintero, A., Ramachandran, S., Raniwala, R., Raniwala, S., Ray, R. L., Riley, C. K., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ross, J. F., Roy, A., Ruan, L., Rusnak, J., Sahoo, N. R., Sahu, P. K., Sakrejda, I., Salur, S., Sandacz, A., Sandweiss, J., Sangaline, E., Sarkar, A., Schambach, J., Scharenberg, R. P., Schmah, A. M., Schmidke, W. B., Schmitz, N., Seger, J., Seyboth, P., Shah, N., Shahaliev, E., Shanmuganathan, P. V., Shao, M., Sharma, B., Shen, W. Q., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Singaraju, R. N., Skoby, M. J., Smirnov, D., Smirnov, N., Solanki, D., Sorensen, P., deSouza, U. G., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Stevens, J. R., Stock, R., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Sumbera, M., Sun, X., Sun, X. M., Sun, Y., Sun, Z., Surrow, B., Svirida, D. N., Symons, T. J. M., de Toledo, A. Szanto, Takahashi, J., Tang, A. H., Tang, Z., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Tlusty, D., Tokarev, M., Trentalange, S., Tribble, R. E., Tribedy, P., Trzeciak, B. A., Tsai, O. D., Turnau, J., Ullrich, T., Underwood, D. G., Van Buren, G., van Nieuwenhuizen, G., Vanfossen, Jr., J. A., Varma, R., Vasconcelos, G. M. S., Vasiliev, A. N., Vertesi, R., Videbæk, F., Viyogi, Y. P., Vokal, S., Vossen, A., Wada, M., Walker, M., Wang, F., Wang, G., Wang, H., Wang, J. S., Wang, X. L., Wang, Y., Webb, G., Webb, J. C., Westfall, G. D., Wieman, H., Wissink, S. W., Witt, R., Wu, Y. F., Xiao, Z., Xie, W., Xin, K., Xu, H., Xu, N., Xu, Q. H., Xu, Y., Xu, Z., Yan, W., Yang, C., Yang, Y., Ye, Z., Yepes, P., Yi, L., Yip, K., Yoo, I-K., Zawisza, Y., Zbroszczyk, H., Zha, W., Zhang, J. B., Zhang, S., Zhang, X. P., Zhang, Y., Zhang, Z. P., Zhao, F., Zhao, J., Zhong, C., Zhu, X., Zhu, Y. H., Zoulkarneeva, Y., and Zyzak, M.

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

We report the beam energy (\sqrt s_{NN} = 7.7 - 200 GeV) and collision centrality dependence of the mean (M), standard deviation (\sigma), skewness (S), and kurtosis (\kappa) of the net-proton multiplicity distributions in Au+Au collisions. The measurements are carried out by the STAR experiment at midrapidity (|y| < 0.5) and within the transverse momentum range 0.4 < pT < 0.8 GeV/c in the first phase of the Beam Energy Scan program at the Relativistic Heavy Ion Collider. These measurements are important for understanding the Quantum Chromodynamic (QCD) phase diagram. The products of the moments, S\sigma and \kappa\sigma^{2}, are sensitive to the correlation length of the hot and dense medium created in the collisions and are related to the ratios of baryon number susceptibilities of corresponding orders. The products of moments are found to have values significantly below the Skellam expectation and close to expectations based on independent proton and anti-proton production. The measurements are compared to a transport model calculation to understand the effect of acceptance and baryon number conservation, and also to a hadron resonance gas model., Comment: 7 pages and 4 figures

Published
2013
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26. Neutral pion cross section and spin asymmetries at intermediate pseudorapidity in polarized proton collisions at sqrt{s} = 200 GeV

Author

STAR Collaboration, Adamczyk, L., Adkins, J. K., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alekseev, I., Alford, J., Anson, C. D., Aparin, A., Arkhipkin, D., Aschenauer, E. C., Averichev, G. S., Balewski, J., Banerjee, A., Barber, B., Barnovska, Z., Beavis, D. R., Bellwied, R., Bhasin, A., Bhati, A. K., Bhattarai, P., Bichsel, H., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Borowski, W., Bouchet, J., Brandin, A. V., Bridgeman, A., Brovko, S. G., Bültmann, S., Bunzarov, I., Burton, T. P., Butterworth, J., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Cendejas, R., Cervantes, M. C., Chaloupka, P., Chang, Z., Chattopadhyay, S., Chen, H. F., Chen, J. H., Chen, L., Cheng, J., Cherney, M., Chikanian, A., Christie, W., Chwastowski, J., Codrington, M. J. M., Corliss, R., Cramer, J. G., Crawford, H. J., Cui, X., Das, S., Leyva, A. Davila, De Silva, L. C., Debbe, R. R., Dedovich, T. G., Deng, J., Derevschikov, A. A., de Souza, R. Derradi, Dhamija, S., di Ruzza, B., Didenko, L., Dilks, C., Ding, F., Djawotho, P., Dong, X., Drachenberg, J. L., Draper, J. E., Du, C. M., Dunkelberger, L. E., Dunlop, J. C., Efimov, L. G., Engelage, J., Engle, K. S., Eppley, G., Eun, L., Evdokimov, O., Fatemi, R., Fazio, S., Fedorisin, J., Filip, P., Finch, E., Fisyak, Y., Flores, C. E., Gagliardi, C. A., Gangadharan, D. R., Garand, D., Geurts, F., Gibson, A., Girard, M., Gliske, S., Grosnick, D., Guo, Y., Gupta, A., Gupta, S., Guryn, W., Haag, B., Hajkova, O., Hamed, A., Han, L-X., Haque, R., Harris, J. W., Hays-Wehle, J. P., He, W., Heppelmann, S., Hirsch, A., Hoffmann, G. W., Hofman, D. J., Horvat, S., Huang, B., Huang, H. Z., Huck, P., Humanic, T. J., Igo, G., Jacobs, W. W., Jang, H., Judd, E. G., Kabana, S., Kalinkin, D., Kang, K., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kesich, A., Khan, Z. H., Kikola, D. P., Kisel, I., Kisiel, A., Koetke, D. D., Kollegger, T., Konzer, J., Koralt, I., Korsch, W., Kotchenda, L., Kravtsov, P., Krueger, K., Kulakov, I., Kumar, L., Kycia, R. A., Lamont, M. A. C., Landgraf, J. M., Landry, K. D., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Leight, W., LeVine, M. J., Li, C., Li, W., Li, X., Li, Y., Li, Z. M., Lima, L. M., Lisa, M. A., Liu, F., Ljubicic, T., Llope, W. J., Longacre, R. S., Luo, X., Ma, G. L., Ma, Y. G., Don, D. M. M. D. Madagodagettige, Mahapatra, D. P., Majka, R., Manweiler, R., Margetis, S., Markert, C., Masui, H., Matis, H. S., McDonald, D., McShane, T. S., Minaev, N. G., Mioduszewski, S., Mohanty, B., Mondal, M. M., Morozov, D. A., Munhoz, M. G., Mustafa, M. K., Nandi, B. K., Nasim, Md., Nayak, T. K., Nelson, J. M., Nogach, L. V., Noh, S. Y., Nord, P. M., Novak, J., Nurushev, S. B., Odyniec, G., Ogawa, A., Oh, K., Ohlson, A., Okorokov, V., Oldag, E. W., Oliveira, R. A. N., Pachr, M., Page, B. S., Pal, S. K., Pan, Y. X., Pandit, Y., Panebratsev, Y., Pawlak, T., Pawlik, B., Pei, H., Perkins, C., Peryt, W., Peterson, A., Pile, P., Planinic, M., Pluta, J., Plyku, D., Pochron, W., Poljak, N., Porter, J., Poskanzer, A. M., Pruthi, N. K., Przybycien, M., Pujahari, P. R., Qiu, H., Quintero, A., Ramachandran, S., Raniwala, R., Raniwala, S., Ray, R. L., Riley, C. K., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ross, J. F., Roy, A., Ruan, L., Rusnak, J., Sahoo, N. R., Sahu, P. K., Sakrejda, I., Salur, S., Sandacz, A., Sandweiss, J., Sangaline, E., Sarkar, A., Schambach, J., Scharenberg, R. P., Schaub, J., Schmah, A. M., Schmidke, W. B., Schmitz, N., Seger, J., Selyuzhenkov, I., Seyboth, P., Shah, N., Shahaliev, E., Shanmuganathan, P. V., Shao, M., Sharma, B., Shen, W. Q., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Singaraju, R. N., Skoby, M. J., Smirnov, D., Smirnov, N., Solanki, D., Sorensen, P., deSouza, U. G., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Stevens, J. R., Stock, R., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Sumbera, M., Sun, X., Sun, X. M., Sun, Y., Sun, Z., Surrow, B., Svirida, D. N., Symons, T. J. M., de Toledo, A. Szanto, Takahashi, J., Tang, A. H., Tang, Z., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Tlusty, D., Tokarev, M., Trentalange, S., Tribble, R. E., Tribedy, P., Trzeciak, B. A., Tsai, O. D., Turnau, J., Ullrich, T., Underwood, D. G., Van Buren, G., van Nieuwenhuizen, G., Vanfossen, Jr., J. A., Varma, R., Vasconcelos, G. M. S., Vasiliev, A. N., Vertesi, R., Videbæk, F., Viyogi, Y. P., Vokal, S., Vossen, A., Wada, M., Walker, M., Wang, F., Wang, G., Wang, H., Wang, J. S., Wang, X. L., Wang, Y., Webb, G., Webb, J. C., Westfall, G. D., Wieman, H., Wissink, S. W., Witt, R., Wu, Y. F., Xiao, Z., Xie, W., Xin, K., Xu, H., Xu, N., Xu, Q. H., Xu, Y., Xu, Z., Yan, W., Yang, C., Yang, Y., Ye, Z., Yepes, P., Yi, L., Yip, K., Yoo, I-K., Zawisza, Y., Zbroszczyk, H., Zha, W., Zhang, J. B., Zhang, S., Zhang, X. P., Zhang, Y., Zhang, Z. P., Zhao, F., Zhao, J., Zhong, C., Zhu, X., Zhu, Y. H., Zoulkarneeva, Y., and Zyzak, M.

Subjects
Nuclear Experiment, High Energy Physics - Experiment
Abstract

The differential cross section and spin asymmetries for neutral pions produced within the intermediate pseudorapidity range 0.8 < {\eta} < 2.0 in polarized proton-proton collisions at sqrt{s} = 200 GeV are presented. Neutral pions were detected using the endcap electromagnetic calorimeter in the STAR detector at RHIC. The cross section was measured over a transverse momentum range of 5 < p_T < 16 GeV/c and is found to be within the scale uncertainty of a next-to-leading order perturbative QCD calculation. The longitudinal double-spin asymmetry, A_LL, is measured in the same pseudorapidity range. This quantity is sensitive to the gluonic contribution to the proton spin, {\Delta}g(x), at low Bjorken-x (down to x approx 0.01), where it is less constrained by measurements at central pseudorapidity. The measured A_LL is consistent with model predictions. The parity-violating asymmetry, A_L, is also measured and found to be consistent with zero. The transverse single-spin asymmetry, A_N, is measured within a previously unexplored kinematic range in Feynman-x and p_T. Such measurements may aid our understanding of the on-set and kinematic dependence of the large asymmetries observed at more forward pseudorapidity ({\eta} approx 3) and their underlying mechanisms. The A_N results presented are consistent with a twist-3 model prediction of a small asymmetry within the present kinematic range., Comment: 11 pages, 9 figures, REVTeX 4.1, Submitted to Phys. Rev. D. Changes for version 2: minor textual updates, modified discussion of gluonic polarization, clarified description of Fig. 4, and corrected sign convention in Fig. 8

Published
2013
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27. Measurement of Charge Multiplicity Asymmetry Correlations in High Energy Nucleus-Nucleus Collisions at 200 GeV

Author

STAR Collaboration, Adamczyk, L., Adkins, J. K., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alakhverdyants, A. V., Alekseev, I., Alford, J., Anson, C. D., Arkhipkin, D., Aschenauer, E., Averichev, G. S., Balewski, J., Banerjee, A., Barnovska, Z., Beavis, D. R., Bellwied, R., Betancourt, M. J., Betts, R. R., Bhasin, A., Bhati, A. K., Bichsel, H., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Borowski, W., Bouchet, J., Brandin, A. V., Brovko, S. G., Bruna, E., Bültmann, S., Bunzarov, I., Burton, T. P., Butterworth, J., Cai, X. Z., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Cendejas, R., Cervantes, M. C., Chaloupka, P., Chang, Z., Chattopadhyay, S., Chen, H. F., Chen, J. H., Chen, J. Y., Chen, L., Cheng, J., Cherney, M., Chikanian, A., Christie, W., Chung, P., Chwastowski, J., Codrington, M. J. M., Corliss, R., Cramer, J. G., Crawford, H. J., Cui, X., Das, S., Leyva, A. Davila, De Silva, L. C., Debbe, R. R., Dedovich, T. G., Deng, J., de Souza, R. Derradi, Dhamija, S., Didenko, L., Ding, F., Dion, A., Djawotho, P., Dong, X., Drachenberg, J. L., Draper, J. E., Du, C. M., Dunkelberger, L. E., Dunlop, J. C., Efimov, L. G., Elnimr, M., Engelage, J., Eppley, G., Eun, L., Evdokimov, O., Fatemi, R., Fazio, S., Fedorisin, J., Fersch, R. G., Filip, P., Finch, E., Fisyak, Y., Flores, E., Gagliardi, C. A., Gangadharan, D. R., Garand, D., Geurts, F., Gibson, A., Gliske, S., Gorbunov, Y. N., Grebenyuk, O. G., Grosnick, D., Gupta, A., Gupta, S., Guryn, W., Haag, B., Hajkova, O., Hamed, A., Han, L-X., Harris, J. W., Hays-Wehle, J. P., Heppelmann, S., Hirsch, A., Hoffmann, G. W., Hofman, D. J., Horvat, S., Huang, B., Huang, H. Z., Huck, P., Humanic, T. J., Igo, G., Jacobs, W. W., Jena, C., Judd, E. G., Kabana, S., Kang, K., Kapitan, J., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kesich, A., Kikola, D. P., Kiryluk, J., Kisel, I., Kisiel, A., Kizka, V., Koetke, D. D., Kollegger, T., Konzer, J., Koralt, I., Koroleva, L., Korsch, W., Kotchenda, L., Kravtsov, P., Krueger, K., Kulakov, I., Kumar, L., Lamont, M. A. C., Landgraf, J. M., Landry, K. D., LaPointe, S., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Leight, W., LeVine, M. J., Li, C., Li, W., Li, X., Li, Y., Li, Z. M., Lima, L. M., Lisa, M. A., Liu, F., Ljubicic, T., Llope, W. J., Longacre, R. S., Lu, Y., Luo, X., Luszczak, A., Ma, G. L., Ma, Y. G., Don, D. M. M. D. Madagodagettige, Mahapatra, D. P., Majka, R., Margetis, S., Markert, C., Masui, H., Matis, H. S., McDonald, D., McShane, T. S., Mioduszewski, S., Mitrovski, M. K., Mohammed, Y., Mohanty, B., Mondal, M. M., Morozov, B., Munhoz, M. G., Mustafa, M. K., Naglis, M., Nandi, B. K., Nasim, Md., Nayak, T. K., Nelson, J. M., Nogach, L. V., Novak, J., Odyniec, G., Ogawa, A., Oh, K., Ohlson, A., Okorokov, V., Oldag, E. W., Oliveira, R. A. N., Olson, D., Ostrowski, P., Pachr, M., Page, B. S., Pal, S. K., Pan, Y. X., Pandit, Y., Panebratsev, Y., Pawlak, T., Pawlik, B., Pei, H., Perkins, C., Peryt, W., Pile, P., Planinic, M., Pluta, J., Poljak, N., Porter, J., Powell, C. B., Pruthi, N. K., Przybycien, M., Pujahari, P. R., Putschke, J., Qiu, H., Ramachandran, S., Raniwala, R., Raniwala, S., Ray, R. L., Redwine, R., Riley, C. K., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ross, J. F., Ruan, L., Rusnak, J., Sahoo, N. R., Sahu, P. K., Sakrejda, I., Salur, S., Sandacz, A., Sandweiss, J., Sangaline, E., Sarkar, A., Schambach, J., Scharenberg, R. P., Schmah, A. M., Schmidke, B., Schmitz, N., Schuster, T. R., Seele, J., Seger, J., Selyuzhenkov, I., Seyboth, P., Shah, N., Shahaliev, E., Shao, M., Sharma, B., Sharma, M., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Singaraju, R. N., Skoby, M. J., Smirnov, D., Smirnov, N., Solanki, D., Sorensen, P., deSouza, U. G., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Steadman, S. G., Stevens, J. R., Stock, R., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Suarez, M. C., Sumbera, M., Sun, X. M., Sun, Y., Sun, Z., Surrow, B., Svirida, D. N., Symons, T. J. M., de Toledo, A. Szanto, Takahashi, J., Tang, A. H., Tang, Z., Tarini, L. H., Tarnowsky, T., Thomas, J. H., Tian, J., Timmins, A. R., Tlusty, D., Tokarev, M., Trentalange, S., Tribble, R. E., Tribedy, P., Trzeciak, B. A., Tsai, O. D., Turnau, J., Ullrich, T., Underwood, D. G., Van Buren, G., van Nieuwenhuizen, G., Vanfossen, Jr., J. A., Varma, R., Vasconcelos, G. M. S., Videbæk, F., Viyogi, Y. P., Vokal, S., Vossen, A., Wada, M., Wang, F., Wang, H., Wang, J. S., Wang, Q., Wang, X. L., Wang, Y., Webb, G., Webb, J. C., Westfall, G. D., Whitten Jr., C., Wieman, H., Wissink, S. W., Witt, R., Wu, Y. F., Xiao, Z., Xie, W., Xin, K., Xu, H., Xu, N., Xu, Q. H., Xu, W., Xu, Y., Xu, Z., Xue, L., Yang, Y., Yepes, P., Yi, L., Yip, K., Yoo, I-K., Zawisza, M., Zbroszczyk, H., Zhang, J. B., Zhang, S., Zhang, X. P., Zhang, Y., Zhang, Z. P., Zhao, F., Zhao, J., Zhong, C., Zhu, X., Zhu, Y. H., Zoulkarneeva, Y., and Zyzak, M.

Subjects
Nuclear Experiment, Nuclear Theory
Abstract

A study is reported of the same- and opposite-sign charge-dependent azimuthal correlations with respect to the event plane in Au+Au collisions at 200 GeV. The charge multiplicity asymmetries between the up/down and left/right hemispheres relative to the event plane are utilized. The contributions from statistical fluctuations and detector effects were subtracted from the (co-)variance of the observed charge multiplicity asymmetries. In the mid- to most-central collisions, the same- (opposite-) sign pairs are preferentially emitted in back-to-back (aligned on the same-side) directions. The charge separation across the event plane, measured by the difference, $\Delta$, between the like- and unlike-sign up/down $-$ left/right correlations, is largest near the event plane. The difference is found to be proportional to the event-by-event final-state particle ellipticity (via the observed second-order harmonic $v^{\rm obs}_{2}$), where $\Delta=(1.3\pm1.4({\rm stat})^{+4.0}_{-1.0}({\rm syst}))\times10^{-5}+(3.2\pm0.2({\rm stat})^{+0.4}_{-0.3}({\rm syst}))\times10^{-3}v^{\rm obs}_{2}$ for 20-40% Au+Au collisions. The implications for the proposed chiral magnetic effect are discussed., Comment: 27 pages, 25 figures, 2 tables

Published
2013
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28. Gluon polarization and jet production at STAR

Author

Djawotho, Pibero

Subjects
Nuclear Experiment
Abstract

At RHIC kinematics, polarized jet hadroproduction is dominated by $gg$ and $qg$ scattering, making the jet longitudinal double-spin asymmetry, $A_{LL}$, sensitive to gluon polarization in the nucleon. I will present STAR results of $A_{LL}$ from inclusive jet and dijet measurements for the RHIC 2006 run totaling 5.5 pb$^{-1}$ of integrated luminosity with 55% beam polarization at center-of-mass energy 200 GeV. I will also present preliminary results from the analyses of data from the 2009 run, which collected a much larger sample (25 pb$^{-1}$ with 57% polarization) at 200 GeV. The results are compared with theoretical calculations of $A_{LL}$ based on various models of the polarized gluon distribution function in the nucleon. The STAR data place significant constraints on allowed theoretical models.

Published
2013
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29. Jet-Hadron Correlations in sqrt{s_{NN}} = 200 GeV p+p and Central Au+Au Collisions

Author

STAR Collaboration, Adamczyk, L., Adkins, J. K., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alekseev, I., Alford, J., Anson, C. D., Aparin, A., Arkhipkin, D., Aschenauer, E. C., Averichev, G. S., Banerjee, A., Beavis, D. R., Bellwied, R., Bhasin, A., Bhati, A. K., Bhattarai, P., Bichsel, H., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Borowski, W., Bouchet, J., Brandin, A. V., Brovko, S. G., Bültmann, S., Bunzarov, I., Burton, T. P., Butterworth, J., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Cendejas, R., Cervantes, M. C., Chaloupka, P., Chang, Z., Chattopadhyay, S., Chen, H. F., Chen, J. H., Chen, L., Cheng, J., Cherney, M., Chikanian, A., Christie, W., Chwastowski, J., Codrington, M. J. M., Contin, G., Cramer, J. G., Crawford, H. J., Cui, X., Das, S., Leyva, A. Davila, De Silva, L. C., Debbe, R. R., Dedovich, T. G., Deng, J., Derevschikov, A. A., de Souza, R. Derradi, Dhamija, S., di Ruzza, B., Didenko, L., Dilks, C., Ding, F., Djawotho, P., Dong, X., Drachenberg, J. L., Draper, J. E., Du, C. M., Dunkelberger, L. E., Dunlop, J. C., Efimov, L. G., Engelage, J., Engle, K. S., Eppley, G., Eun, L., Evdokimov, O., Eyser, O., Fatemi, R., Fazio, S., Fedorisin, J., Filip, P., Finch, E., Fisyak, Y., Flores, C. E., Gagliardi, C. A., Gangadharan, D. R., Garand, D., Geurts, F., Gibson, A., Girard, M., Gliske, S., Greiner, L., Grosnick, D., Gunarathne, D. S., Guo, Y., Gupta, A., Gupta, S., Guryn, W., Haag, B., Hamed, A., Han, L-X., Haque, R., Harris, J. W., Heppelmann, S., Hirsch, A., Hoffmann, G. W., Hofman, D. J., Horvat, S., Huang, B., Huang, H. Z., Huang, X., Huck, P., Humanic, T. J., Igo, G., Jacobs, W. W., Jang, H., Judd, E. G., Kabana, S., Kalinkin, D., Kang, K., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kesich, A., Khan, Z. H., Kikola, D. P., Kisel, I., Kisiel, A., Koetke, D. D., Kollegger, T., Konzer, J., Koralt, I., Kotchenda, L., Kraishan, A. F., Kravtsov, P., Krueger, K., Kulakov, I., Kumar, L., Kycia, R. A., Lamont, M. A. C., Landgraf, J. M., Landry, K. D., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., LeVine, M. J., Li, C., Li, W., Li, X., Li, Y., Li, Z. M., Lisa, M. A., Liu, F., Ljubicic, T., Llope, W. J., Lomnitz, M., Longacre, R. S., Luo, X., Ma, G. L., Ma, Y. G., Don, D. M. M. D. Madagodagettige, Mahapatra, D. P., Majka, R., Margetis, S., Markert, C., Masui, H., Matis, H. S., McDonald, D., McShane, T. S., Minaev, N. G., Mioduszewski, S., Mohanty, B., Mondal, M. M., Morozov, D. A., Mustafa, M. K., Nandi, B. K., Nasim, Md., Nayak, T. K., Nelson, J. M., Nigmatkulov, G., Nogach, L. V., Noh, S. Y., Novak, J., Nurushev, S. B., Odyniec, G., Ogawa, A., Oh, K., Ohlson, A., Okorokov, V., Oldag, E. W., Olvitt Jr., D. L., Pachr, M., Page, B. S., Pal, S. K., Pan, Y. X., Pandit, Y., Panebratsev, Y., Pawlak, T., Pawlik, B., Pei, H., Perkins, C., Peryt, W., Pile, P., Planinic, M., Pluta, J., Poljak, N., Porter, J., Poskanzer, A. M., Pruthi, N. K., Przybycien, M., Pujahari, P. R., Putschke, J., Qiu, H., Quintero, A., Ramachandran, S., Raniwala, R., Raniwala, S., Ray, R. L., Riley, C. K., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ross, J. F., Roy, A., Ruan, L., Rusnak, J., Rusnakova, O., Sahoo, N. R., Sahu, P. K., Sakrejda, I., Salur, S., Sandweiss, J., Sangaline, E., Sarkar, A., Schambach, J., Scharenberg, R. P., Schmah, A. M., Schmidke, W. B., Schmitz, N., Seger, J., Seyboth, P., Shah, N., Shahaliev, E., Shanmuganathan, P. V., Shao, M., Sharma, B., Shen, W. Q., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Singaraju, R. N., Skoby, M. J., Smirnov, D., Smirnov, N., Solanki, D., Sorensen, P., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Stevens, J. R., Stock, R., Strikhanov, M., Stringfellow, B., Sumbera, M., Sun, X., Sun, X. M., Sun, Y., Sun, Z., Surrow, B., Svirida, D. N., Symons, T. J. M., Szelezniak, M. A., Takahashi, J., Tang, A. H., Tang, Z., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Tlusty, D., Tokarev, M., Trentalange, S., Tribble, R. E., Tribedy, P., Trzeciak, B. A., Tsai, O. D., Turnau, J., Ullrich, T., Underwood, D. G., Van Buren, G., van Nieuwenhuizen, G., Vandenbroucke, M., Vanfossen Jr., J. A., Varma, R., Vasconcelos, G. M. S., Vasiliev, A. N., Vertesi, R., Videbæk, F., Viyogi, Y. P., Vokal, S., Vossen, A., Wada, M., Wang, F., Wang, G., Wang, H., Wang, J. S., Wang, X. L., Wang, Y., Webb, G., Webb, J. C., Westfall, G. D., Wieman, H., Wissink, S. W., Witt, R., Wu, Y. F., Xiao, Z., Xie, W., Xin, K., Xu, H., Xu, J., Xu, N., Xu, Q. H., Xu, Y., Xu, Z., Yan, W., Yang, C., Yang, Y., Ye, Z., Yepes, P., Yi, L., Yip, K., Yoo, I-K., Yu, N., Zawisza, Y., Zbroszczyk, H., Zha, W., Zhang, J. B., Zhang, J. L., Zhang, S., Zhang, X. P., Zhang, Y., Zhang, Z. P., Zhao, F., Zhao, J., Zhong, C., Zhu, X., Zhu, Y. H., Zoulkarneeva, Y., and Zyzak, M.

Subjects
Nuclear Experiment
Abstract

Azimuthal angular correlations of charged hadrons with respect to the axis of a reconstructed (trigger) jet in Au+Au and p+p collisions at $\sqrt{s_{\text{NN}}} = 200 \text{GeV}$ in STAR are presented. The trigger jet population in Au+Au collisions is biased towards jets that have not interacted with the medium, allowing easier matching of jet energies between Au+Au and p+p collisions while enhancing medium effects on the recoil jet. The associated hadron yield of the recoil jet is significantly suppressed at high transverse momentum ($p_{\text{T}}^{\text{assoc}}$) and enhanced at low $p_{\text{T}}^{\text{assoc}}$ in 0-20% central Au+Au collisions compared to p+p collisions, which is indicative of medium-induced parton energy loss in ultrarelativistic heavy-ion collisions., Comment: v2 is the version accepted by PRL

Published
2013
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30. Fluctuations of charge separation perpendicular to the event plane and local parity violation in sqrt(sNN)=200 GeV Au+Au collisions at RHIC

Author

STAR Collaboration, Adamczyk, L., Adkins, J. K., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alekseev, I., Alford, J., Anson, C. D., Aparin, A., Arkhipkin, D., Aschenauer, E., Averichev, G. S., Balewski, J., Banerjee, A., Barnovska, Z., Beavis, D. R., Bellwied, R., Betancourt, M. J., Betts, R. R., Bhasin, A., Bhati, A. K., Bhattarai, Bichsel, H., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Borowski, W., Bouchet, J., Brandin, A. V., Brovko, S. G., Bruna, E., Bültmann, S., Bunzarov, I., Burton, T. P., Butterworth, J., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Cendejas, R., Cervantes, M. C., Chaloupka, P., Chang, Z., Chattopadhyay, S., Chen, H. F., Chen, J. H., Chen, J. Y., Chen, L., Cheng, J., Cherney, M., Chikanian, A., Christie, W., Chung, P., Chwastowski, J., Codrington, M. J. M., Corliss, R., Cramer, J. G., Crawford, H. J., Cui, X., Das, S., Leyva, A. Davila, De Silva, L. C., Debbe, R. R., Dedovich, T. G., Deng, J., de Souza, R. Derradi, Dhamija, S., di Ruzza, B., Didenko, L., Dilks, Ding, F., Dion, A., Djawotho, P., Dong, X., Drachenberg, J. L., Draper, J. E., Du, C. M., Dunkelberger, L. E., Dunlop, J. C., Efimov, L. G., Elnimr, M., Engelage, J., Engle, K. S., Eppley, G., Eun, L., Evdokimov, O., Fatemi, R., Fazio, S., Fedorisin, J., Fersch, R. G., Filip, P., Finch, E., Fisyak, Y., Flores, C. E., Gagliardi, C. A., Gangadharan, D. R., Garand, D., Geurts, F., Gibson, A., Gliske, S., Grebenyuk, O. G., Grosnick, D., Guo, Y., Gupta, A., Gupta, S., Guryn, W., Haag, B., Hajkova, O., Hamed, A., Han, L-X., Haque, R., Harris, J. W., Hays-Wehle, J. P., Heppelmann, S., Hirsch, A., Hoffmann, G. W., Hofman, D. J., Horvat, S., Huang, B., Huang, H. Z., Huck, P., Humanic, T. J., Igo, G., Jacobs, W. W., Jena, C., Judd, E. G., Kabana, S., Kang, K., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kesich, A., Kikola, D. P., Kiryluk, J., Kisel, I., Kisiel, A., Koetke, D. D., Kollegger, T., Konzer, J., Koralt, I., Korsch, W., Kotchenda, L., Kravtsov, P., Krueger, K., Kulakov, I., Kumar, L., Kycia, R. A., Lamont, M. A. C., Landgraf, J. M., Landry, K. D., LaPointe, S., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Leight, W., LeVine, M. J., Li, C., Li, W., Li, X., Li, Y., Li, Z. M., Lima, L. M., Lisa, M. A., Liu, F., Ljubicic, T., Llope, W. J., Longacre, R. S., Luo, X., Ma, G. L., Ma, Y. G., Don, D. M. M. D. Madagodagettige, Mahapatra, D. P., Majka, R., Margetis, S., Markert, C., Masui, H., Matis, H. S., McDonald, D., McShane, T. S., Mioduszewski, S., Mitrovski, M. K., Mohammed, Y., Mohanty, B., Mondal, M. M., Munhoz, M. G., Mustafa, M. K., Naglis, M., Nandi, B. K., Nasim, Md., Nayak, T. K., Nelson, J. M., Nogach, L. V., Novak, J., Odyniec, G., Ogawa, A., Oh, K., Ohlson, A., Okorokov, V., Oldag, E. W., Oliveira, R. A. N., Olson, D., Pachr, M., Page, B. S., Pal, S. K., Pan, Y. X., Pandit, Y., Panebratsev, Y., Pawlak, T., Pawlik, B., Pei, H., Perkins, C., Peryt, W., Pile, P., Planinic, M., Pluta, J., Plyku, D., Poljak, N., Porter, J., Poskanzer, A. M., Powell, C. B., Pruneau, C., Pruthi, N. K., Przybycien, M., Pujahari, P. R., Putschke, J., Qiu, H., Ramachandran, S., Raniwala, R., Raniwala, S., Ray, R. L., Riley, C. K., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ross, J. F., Roy, A., Ruan, L., Rusnak, J., Sahoo, N. R., Sahu, P. K., Sakrejda, I., Salur, S., Sandacz, A., Sandweiss, J., Sangaline, E., Sarkar, A., Schambach, J., Scharenberg, R. P., Schmah, A. M., Schmidke, B., Schmitz, N., Schuster, T. R., Seger, J., Seyboth, P., Shah, N., Shahaliev, E., Shao, M., Sharma, B., Sharma, M., Shen, W. Q., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Singaraju, R. N., Skoby, M. J., Smirnov, D., Smirnov, N., Solanki, D., Sorensen, P., deSouza, U. G., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Stevens, J. R., Stock, R., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Suarez, M. C., Sumbera, M., Sun, X. M., Sun, Y., Sun, Z., Surrow, B., Svirida, D. N., Symons, T. J. M., de Toledo, A. Szanto, Takahashi, J., Tang, A. H., Tang, Z., Tarini, L. H., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Tlusty, D., Tokarev, M., Trentalange, S., Tribble, R. E., Tribedy, P., Trzeciak, B. A., Tsai, O. D., Turnau, J., Ullrich, T., Underwood, D. G., Van Buren, G., van Nieuwenhuizen, G., Vanfossen, Jr., J. A., Varma, R., Vasconcelos, G. M. S., Vertesi, R., Videbæk, F., Viyogi, Y. P., Vokal, S., Voloshin, S. A., Vossen, A., Wada, M., Walker, M., Wang, F., Wang, G., Wang, H., Wang, J. S., Wang, Q., Wang, X. L., Wang, Y., Webb, G., Webb, J. C., Westfall, G. D., Wieman, H., Wissink, S. W., Witt, R., Wu, Y. F., Xiao, Z., Xie, W., Xin, K., Xu, H., Xu, N., Xu, Q. H., Xu, W., Xu, Y., Xu, Z., Yan, Yang, C., Yang, Y., Yepes, P., Yi, L., Yip, K., Yoo, I-K., Zawisza, Y., Zbroszczyk, H., Zha, W., Zhang, J. B., Zhang, S., Zhang, X. P., Zhang, Y., Zhang, Z. P., Zhao, F., Zhao, J., Zhong, C., Zhu, X., Zhu, Y. H., Zoulkarneeva, Y., and Zyzak, M.

Subjects
Nuclear Experiment
Abstract

Previous experimental results based on data (15 million events) collected by the STAR detector at RHIC suggest event-by-event charge separation fluctuations perpendicular to the event plane in non-central heavy-ion collisions. Here we present the correlator previously used split into its two component parts to reveal correlations parallel and perpendicular to the event plane. The results are from a high statistics 200 GeV Au+Au collisions data set (57 million events) collected by the STAR experiment. We explicitly count units of charge separation from which we find clear evidence for more charge separation fluctuations perpendicular than parallel to the event plane. We also employ a modified correlator to study the possible P-even background in same and opposite charge correlations, and find that the P-even background may largely be explained by momentum conservation and collective motion., Comment: 10 pages, 9 figures

Published
2013

31. Freeze-out Dynamics via Charged Kaon Femtoscopy in sqrt(sNN)=200 GeV Central Au+Au Collisions

Author

STAR Collaboration, Adamczyk, L., Adkins, J. K., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alekseev, I., Alford, J., Anson, C. D., Aparin, A., Arkhipkin, D., Aschenauer, E., Averichev, G. S., Balewski, J., Banerjee, A., Barnovska, Z., Beavis, D. R., Bellwied, R., Betancourt, M. J., Betts, R. R., Bhasin, A., Bhati, A. K., Bhattarai, Bichsel, H., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Borowski, W., Bouchet, J., Brandin, A. V., Brovko, S. G., Bruna, E., Bültmann, S., Bunzarov, I., Burton, T. P., Butterworth, J., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Cendejas, R., Cervantes, M. C., Chaloupka, P., Chang, Z., Chattopadhyay, S., Chen, H. F., Chen, J. H., Chen, J. Y., Chen, L., Cheng, J., Cherney, M., Chikanian, A., Christie, W., Chung, P., Chwastowski, J., Codrington, M. J. M., Corliss, R., Cramer, J. G., Crawford, H. J., Cui, X., Das, S., Leyva, A. Davila, De Silva, L. C., Debbe, R. R., Dedovich, T. G., Deng, J., de Souza, R. Derradi, Dhamija, S., di Ruzza, B., Didenko, L., Dilks, Ding, F., Dion, A., Djawotho, P., Dong, X., Drachenberg, J. L., Draper, J. E., Du, C. M., Dunkelberger, L. E., Dunlop, J. C., Efimov, L. G., Elnimr, M., Engelage, J., Engle, K. S., Eppley, G., Eun, L., Evdokimov, O., Fatemi, R., Fazio, S., Fedorisin, J., Fersch, R. G., Filip, P., Finch, E., Fisyak, Y., Flores, C. E., Gagliardi, C. A., Gangadharan, D. R., Garand, D., Geurts, F., Gibson, A., Gliske, S., Grebenyuk, O. G., Grosnick, D., Guo, Y., Gupta, A., Gupta, S., Guryn, W., Haag, B., Hajkova, O., Hamed, A., Han, L-X., Haque, R., Harris, J. W., Hays-Wehle, J. P., Heppelmann, S., Hirsch, A., Hoffmann, G. W., Hofman, D. J., Horvat, S., Huang, B., Huang, H. Z., Huck, P., Humanic, T. J., Igo, G., Jacobs, W. W., Jena, C., Judd, E. G., Kabana, S., Kang, K., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kesich, A., Kikola, D. P., Kiryluk, J., Kisel, I., Kisiel, A., Koetke, D. D., Kollegger, T., Konzer, J., Koralt, I., Korsch, W., Kotchenda, L., Kravtsov, P., Krueger, K., Kulakov, I., Kumar, L., Kycia, R. A., Lamont, M. A. C., Landgraf, J. M., Landry, K. D., LaPointe, S., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Leight, W., LeVine, M. J., Li, C., Li, W., Li, X., Li, Y., Li, Z. M., Lima, L. M., Lisa, M. A., Liu, F., Ljubicic, T., Llope, W. J., Longacre, R. S., Luo, X., Ma, G. L., Ma, Y. G., Don, D. M. M. D. Madagodagettige, Mahapatra, D. P., Majka, R., Margetis, S., Markert, C., Masui, H., Matis, H. S., McDonald, D., McShane, T. S., Mioduszewski, S., Mitrovski, M. K., Mohammed, Y., Mohanty, B., Mondal, M. M., Munhoz, M. G., Mustafa, M. K., Naglis, M., Nandi, B. K., Nasim, Md., Nayak, T. K., Nelson, J. M., Nogach, L. V., Novak, J., Odyniec, G., Ogawa, A., Oh, K., Ohlson, A., Okorokov, V., Oldag, E. W., Oliveira, R. A. N., Olson, D., Pachr, M., Page, B. S., Pal, S. K., Pan, Y. X., Pandit, Y., Panebratsev, Y., Pawlak, T., Pawlik, B., Pei, H., Perkins, C., Peryt, W., Pile, P., Planinic, M., Pluta, J., Plyku, D., Poljak, N., Porter, J., Poskanzer, A. M., Powell, C. B., Pruneau, C., Pruthi, N. K., Przybycien, M., Pujahari, P. R., Putschke, J., Qiu, H., Ramachandran, S., Raniwala, R., Raniwala, S., Ray, R. L., Riley, C. K., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ross, J. F., Roy, A., Ruan, L., Rusnak, J., Sahoo, N. R., Sahu, P. K., Sakrejda, I., Salur, S., Sandacz, A., Sandweiss, J., Sangaline, E., Sarkar, A., Schambach, J., Scharenberg, R. P., Schmah, A. M., Schmidke, B., Schmitz, N., Schuster, T. R., Seger, J., Seyboth, P., Shah, N., Shahaliev, E., Shao, M., Sharma, B., Sharma, M., Shen, W. Q., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Singaraju, R. N., Skoby, M. J., Smirnov, D., Smirnov, N., Solanki, D., Sorensen, P., deSouza, U. G., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Stevens, J. R., Stock, R., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Suarez, M. C., Sumbera, M., Sun, X. M., Sun, Y., Sun, Z., Surrow, B., Svirida, D. N., Symons, T. J. M., de Toledo, A. Szanto, Takahashi, J., Tang, A. H., Tang, Z., Tarini, L. H., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Tlusty, D., Tokarev, M., Trentalange, S., Tribble, R. E., Tribedy, P., Trzeciak, B. A., Tsai, O. D., Turnau, J., Ullrich, T., Underwood, D. G., Van Buren, G., van Nieuwenhuizen, G., Vanfossen, Jr., J. A., Varma, R., Vasconcelos, G. M. S., Vertesi, R., Videbæk, F., Viyogi, Y. P., Vokal, S., Voloshin, S. A., Vossen, A., Wada, M., Walker, M., Wang, F., Wang, G., Wang, H., Wang, J. S., Wang, Q., Wang, X. L., Wang, Y., Webb, G., Webb, J. C., Westfall, G. D., Wieman, H., Wissink, S. W., Witt, R., Wu, Y. F., Xiao, Z., Xie, W., Xin, K., Xu, H., Xu, N., Xu, Q. H., Xu, W., Xu, Y., Xu, Z., Yan, Yang, C., Yang, Y., Yepes, P., Yi, L., Yip, K., Yoo, I-K., Zawisza, Y., Zbroszczyk, H., Zha, W., Zhang, J. B., Zhang, S., Zhang, X. P., Zhang, Y., Zhang, Z. P., Zhao, F., Zhao, J., Zhong, C., Zhu, X., Zhu, Y. H., Zoulkarneeva, Y., and Zyzak, M.

Subjects
Nuclear Experiment
Abstract

We present measurements of three-dimensional correlation functions of like-sign low transverse momentum kaon pairs from sqrt(sNN)=200 GeV Au+Au collisions. A Cartesian surface-spherical harmonic decomposition technique was used to extract the kaon source function. The latter was found to have a three-dimensional Gaussian shape and can be adequately reproduced by Therminator event generator simulations with resonance contributions taken into account. Compared to the pion one, the kaon source function is generally narrower and does not have the long tail along the pair transverse momentum direction. The kaon Gaussian radii display a monotonic decrease with increasing transverse mass m_T over the interval of 0.55<=m_T<=1.15 GeV/c^2. While the kaon radii are adequately described by the m_T-scaling in the outward and sideward directions, in the longitudinal direction the lowest m_T value exceeds the expectations from a pure hydrodynamical model prediction., Comment: 8 pages, 4 figures

Published
2013
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32. System size dependence of transverse momentum correlations at $\sqrt{s_{NN}}=$ 62.4 and 200 GeV at the BNL Relativistic Heavy Ion Collider

Author

STAR Collaboration, Adamczyk, L., Adkins, J. K., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alekseev, I., Alford, J., Anson, C. D., Aparin, A., Arkhipkin, D., Aschenauer, E., Averichev, G. S., Balewski, J., Banerjee, A., Barnovska, Z., Beavis, D. R., Bellwied, R., Betancourt, M. J., Betts, R. R., Bhasin, A., Bhati, A. K., Bhattarai, Bichsel, H., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Borowski, W., Bouchet, J., Brandin, A. V., Brovko, S. G., Bruna, E., Bültmann, S., Bunzarov, I., Burton, T. P., Butterworth, J., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Cendejas, R., Cervantes, M. C., Chaloupka, P., Chang, Z., Chattopadhyay, S., Chen, H. F., Chen, J. H., Chen, J. Y., Chen, L., Cheng, J., Cherney, M., Chikanian, A., Christie, W., Chung, P., Chwastowski, J., Codrington, M. J. M., Corliss, R., Cramer, J. G., Crawford, H. J., Cui, X., Das, S., Leyva, A. Davila, De Silva, L. C., Debbe, R. R., Dedovich, T. G., Deng, J., de Souza, R. Derradi, Dhamija, S., di Ruzza, B., Didenko, L., Dilks, Ding, F., Dion, A., Djawotho, P., Dong, X., Drachenberg, J. L., Draper, J. E., Du, C. M., Dunkelberger, L. E., Dunlop, J. C., Efimov, L. G., Elnimr, M., Engelage, J., Engle, K. S., Eppley, G., Eun, L., Evdokimov, O., Fatemi, R., Fazio, S., Fedorisin, J., Fersch, R. G., Filip, P., Finch, E., Fisyak, Y., Flores, C. E., Gagliardi, C. A., Gangadharan, D. R., Garand, D., Geurts, F., Gibson, A., Gliske, S., Grebenyuk, O. G., Grosnick, D., Guo, Y., Gupta, A., Gupta, S., Guryn, W., Haag, B., Hajkova, O., Hamed, A., Han, L-X., Haque, R., Harris, J. W., Hays-Wehle, J. P., Heppelmann, S., Hirsch, A., Hoffmann, G. W., Hofman, D. J., Horvat, S., Huang, B., Huang, H. Z., Huck, P., Humanic, T. J., Igo, G., Jacobs, W. W., Jena, C., Judd, E. G., Kabana, S., Kang, K., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kesich, A., Kikola, D. P., Kiryluk, J., Kisel, I., Kisiel, A., Koetke, D. D., Kollegger, T., Konzer, J., Koralt, I., Korsch, W., Kotchenda, L., Kravtsov, P., Krueger, K., Kulakov, I., Kumar, L., Kycia, R. A., Lamont, M. A. C., Landgraf, J. M., Landry, K. D., LaPointe, S., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Leight, W., LeVine, M. J., Li, C., Li, W., Li, X., Li, Y., Li, Z. M., Lima, L. M., Lisa, M. A., Liu, F., Ljubicic, T., Llope, W. J., Longacre, R. S., Luo, X., Ma, G. L., Ma, Y. G., Don, D. M. M. D. Madagodagettige, Mahapatra, D. P., Majka, R., Margetis, S., Markert, C., Masui, H., Matis, H. S., McDonald, D., McShane, T. S., Mioduszewski, S., Mitrovski, M. K., Mohammed, Y., Mohanty, B., Mondal, M. M., Munhoz, M. G., Mustafa, M. K., Naglis, M., Nandi, B. K., Nasim, Md., Nayak, T. K., Nelson, J. M., Nogach, L. V., Novak, J., Odyniec, G., Ogawa, A., Oh, K., Ohlson, A., Okorokov, V., Oldag, E. W., Oliveira, R. A. N., Olson, D., Pachr, M., Page, B. S., Pal, S. K., Pan, Y. X., Pandit, Y., Panebratsev, Y., Pawlak, T., Pawlik, B., Pei, H., Perkins, C., Peryt, W., Pile, P., Planinic, M., Pluta, J., Plyku, D., Poljak, N., Porter, J., Poskanzer, A. M., Powell, C. B., Pruneau, C., Pruthi, N. K., Przybycien, M., Pujahari, P. R., Putschke, J., Qiu, H., Ramachandran, S., Raniwala, R., Raniwala, S., Ray, R. L., Riley, C. K., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ross, J. F., Roy, A., Ruan, L., Rusnak, J., Sahoo, N. R., Sahu, P. K., Sakrejda, I., Salur, S., Sandacz, A., Sandweiss, J., Sangaline, E., Sarkar, A., Schambach, J., Scharenberg, R. P., Schmah, A. M., Schmidke, B., Schmitz, N., Schuster, T. R., Seger, J., Seyboth, P., Shah, N., Shahaliev, E., Shao, M., Sharma, B., Sharma, M., Shen, W. Q., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Singaraju, R. N., Skoby, M. J., Smirnov, D., Smirnov, N., Solanki, D., Sorensen, P., deSouza, U. G., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Stevens, J. R., Stock, R., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Suarez, M. C., Sumbera, M., Sun, X. M., Sun, Y., Sun, Z., Surrow, B., Svirida, D. N., Symons, T. J. M., de Toledo, A. Szanto, Takahashi, J., Tang, A. H., Tang, Z., Tarini, L. H., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Tlusty, D., Tokarev, M., Trentalange, S., Tribble, R. E., Tribedy, P., Trzeciak, B. A., Tsai, O. D., Turnau, J., Ullrich, T., Underwood, D. G., Van Buren, G., van Nieuwenhuizen, G., Vanfossen, Jr., J. A., Varma, R., Vasconcelos, G. M. S., Vertesi, R., Videbæk, F., Viyogi, Y. P., Vokal, S., Voloshin, S. A., Vossen, A., Wada, M., Walker, M., Wang, F., Wang, G., Wang, H., Wang, J. S., Wang, Q., Wang, X. L., Wang, Y., Webb, G., Webb, J. C., Westfall, G. D., Wieman, H., Wissink, S. W., Witt, R., Wu, Y. F., Xiao, Z., Xie, W., Xin, K., Xu, H., Xu, N., Xu, Q. H., Xu, W., Xu, Y., Xu, Z., Yan, Yang, C., Yang, Y., Yepes, P., Yi, L., Yip, K., Yoo, I-K., Zawisza, Y., Zbroszczyk, H., Zha, W., Zhang, J. B., Zhang, S., Zhang, X. P., Zhang, Y., Zhang, Z. P., Zhao, F., Zhao, J., Zhong, C., Zhu, X., Zhu, Y. H., Zoulkarneeva, Y., and Zyzak, M.

Subjects
Nuclear Experiment
Abstract

We present a study of the average transverse momentum ($p_t$) fluctuations and $p_t$ correlations for charged particles produced in Cu+Cu collisions at midrapidity for $\sqrt{s_{NN}} =$ 62.4 and 200 GeV. These results are compared with those published for Au+Au collisions at the same energies, to explore the system size dependence. In addition to the collision energy and system size dependence, the $p_t$ correlation results have been studied as functions of the collision centralities, the ranges in $p_t$, the pseudorapidity $\eta$, and the azimuthal angle $\phi$. The square root of the measured $p_t$ correlations when scaled by mean $p_t$ is found to be independent of both colliding beam energy and system size studied. Transport-based model calculations are found to have a better quantitative agreement with the measurements compared to models which incorporate only jetlike correlations., Comment: 12 pages and 9 figures. Published in Physical Review C

Published
2013
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33. Observation of an energy-dependent difference in elliptic flow between particles and anti-particles in relativistic heavy ion collisions

Author

Adamczyk, L., Adkins, J. K., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alekseev, I., Alford, J., Anson, C. D., Aparin, A., Arkhipkin, D., Aschenauer, E., Averichev, G. S., Balewski, J., Banerjee, A., Barnovska, Z., Beavis, D. R., Bellwied, R., Betancourt, M. J., Betts, R. R., Bhasin, A., Bhati, A. K., Bhattarai, Bichsel, H., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Borowski, W., Bouchet, J., Brandin, A. V., Brovko, S. G., Bruna, E., Bültmann, S., Bunzarov, I., Burton, T. P., Butterworth, J., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Cendejas, R., Cervantes, M. C., Chaloupka, P., Chang, Z., Chattopadhyay, S., Chen, H. F., Chen, J. H., Chen, J. Y., Chen, L., Cheng, J., Cherney, M., Chikanian, A., Christie, W., Chung, P., Chwastowski, J., Codrington, M. J. M., Corliss, R., Cramer, J. G., Crawford, H. J., Cui, X., Das, S., Leyva, A. Davila, De Silva, L. C., Debbe, R. R., Dedovich, T. G., Deng, J., de Souza, R. Derradi, Dhamija, S., di Ruzza, B., Didenko, L., Dilks, Ding, F., Dion, A., Djawotho, P., Dong, X., Drachenberg, J. L., Draper, J. E., Du, C. M., Dunkelberger, L. E., Dunlop, J. C., Efimov, L. G., Elnimr, M., Engelage, J., Engle, K. S., Eppley, G., Eun, L., Evdokimov, O., Fatemi, R., Fazio, S., Fedorisin, J., Fersch, R. G., Filip, P., Finch, E., Fisyak, Y., Flores, C. E., Gagliardi, C. A., Gangadharan, D. R., Garand, D., Geurts, F., Gibson, A., Gliske, S., Grebenyuk, O. G., Grosnick, D., Guo, Y., Gupta, A., Gupta, S., Guryn, W., Haag, B., Hajkova, O., Hamed, A., Han, L-X., Haque, R., Harris, J. W., Hays-Wehle, J. P., Heppelmann, S., Hirsch, A., Hoffmann, G. W., Hofman, D. J., Horvat, S., Huang, B., Huang, H. Z., Huck, P., Humanic, T. J., Igo, G., Jacobs, W. W., Jena, C., Judd, E. G., Kabana, S., Kang, K., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kesich, A., Kikola, D. P., Kiryluk, J., Kisel, I., Kisiel, A., Koetke, D. D., Kollegger, T., Konzer, J., Koralt, I., Korsch, W., Kotchenda, L., Kravtsov, P., Krueger, K., Kulakov, I., Kumar, L., Lamont, M. A. C., Landgraf, J. M., Landry, K. D., LaPointe, S., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Leight, W., LeVine, M. J., Li, C., Li, W., Li, X., Li, Y., Li, Z. M., Lima, L. M., Lisa, M. A., Liu, F., Ljubicic, T., Llope, W. J., Longacre, R. S., Luo, X., Luszczak, A., Ma, G. L., Ma, Y. G., Don, D. M. M. D. Madagodagettige, Mahapatra, D. P., Majka, R., Margetis, S., Markert, C., Masui, H., Matis, H. S., McDonald, D., McShane, T. S., Mioduszewski, S., Mitrovski, M. K., Mohammed, Y., Mohanty, B., Mondal, M. M., Munhoz, M. G., Mustafa, M. K., Naglis, M., Nandi, B. K., Nasim, Md., Nayak, T. K., Nelson, J. M., Nogach, L. V., Novak, J., Odyniec, G., Ogawa, A., Oh, K., Ohlson, A., Okorokov, V., Oldag, E. W., Oliveira, R. A. N., Olson, D., Pachr, M., Page, B. S., Pal, S. K., Pan, Y. X., Pandit, Y., Panebratsev, Y., Pawlak, T., Pawlik, B., Pei, H., Perkins, C., Peryt, W., Pile, P., Planinic, M., Pluta, J., Plyku, D., Poljak, N., Porter, J., Poskanzer, A. M., Powell, C. B., Pruneau, C., Pruthi, N. K., Przybycien, M., Pujahari, P. R., Putschke, J., Qiu, H., Ramachandran, S., Raniwala, R., Raniwala, S., Ray, R. L., Riley, C. K., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ross, J. F., Roy, A., Ruan, L., Rusnak, J., Sahoo, N. R., Sahu, P. K., Sakrejda, I., Salur, S., Sandacz, A., Sandweiss, J., Sangaline, E., Sarkar, A., Schambach, J., Scharenberg, R. P., Schmah, A. M., Schmidke, B., Schmitz, N., Schuster, T. R., Seger, J., Seyboth, P., Shah, N., Shahaliev, E., Shao, M., Sharma, B., Sharma, M., Shen, W. Q., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Singaraju, R. N., Skoby, M. J., Smirnov, D., Smirnov, N., Solanki, D., Sorensen, P., deSouza, U. G., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Stevens, J. R., Stock, R., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Suarez, M. C., Sumbera, M., Sun, X. M., Sun, Y., Sun, Z., Surrow, B., Svirida, D. N., Symons, T. J. M., de Toledo, A. Szanto, Takahashi, J., Tang, A. H., Tang, Z., Tarini, L. H., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Tlusty, D., Tokarev, M., Trentalange, S., Tribble, R. E., Tribedy, P., Trzeciak, B. A., Tsai, O. D., Turnau, J., Ullrich, T., Underwood, D. G., Van Buren, G., van Nieuwenhuizen, G., Vanfossen, Jr., J. A., Varma, R., Vasconcelos, G. M. S., Vertesi, R., Videbæk, F., Viyogi, Y. P., Vokal, S., Voloshin, S. A., Vossen, A., Wada, M., Walker, M., Wang, F., Wang, G., Wang, H., Wang, J. S., Wang, Q., Wang, X. L., Wang, Y., Webb, G., Webb, J. C., Westfall, G. D., Wieman, H., Wissink, S. W., Witt, R., Wu, Y. F., Xiao, Z., Xie, W., Xin, K., Xu, H., Xu, N., Xu, Q. H., Xu, W., Xu, Y., Xu, Z., Yan, Yang, C., Yang, Y., Yepes, P., Yi, L., Yip, K., Yoo, I-K., Zawisza, Y., Zbroszczyk, H., Zha, W., Zhang, J. B., Zhang, S., Zhang, X. P., Zhang, Y., Zhang, Z. P., Zhao, F., Zhao, J., Zhong, C., Zhu, X., Zhu, Y. H., Zoulkarneeva, Y., and Zyzak, M.

Subjects
Nuclear Experiment
Abstract

Elliptic flow ($v_{2}$) values for identified particles at mid-rapidity in Au+Au collisions, measured by the STAR experiment in the Beam Energy Scan at RHIC at $\sqrt{s_{NN}}=$ 7.7--62.4 GeV, are presented. A beam-energy dependent difference of the values of $v_{2}$ between particles and corresponding anti-particles was observed. The difference increases with decreasing beam energy and is larger for baryons compared to mesons. This implies that, at lower energies, particles and anti-particles are not consistent with the universal number-of-constituent-quark (NCQ) scaling of $v_{2}$ that was observed at $\sqrt{s_{NN}}=$ 200 GeV.

Published
2013
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34. Elliptic flow of identified hadrons in Au+Au collisions at $\sqrt{s_{NN}}=$ 7.7--62.4 GeV

Author

Adamczyk, L., Adkins, J. K., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alekseev, I., Alford, J., Anson, C. D., Aparin, A., Arkhipkin, D., Aschenauer, E., Averichev, G. S., Balewski, J., Banerjee, A., Barnovska, Z., Beavis, D. R., Bellwied, R., Betancourt, M. J., Betts, R. R., Bhasin, A., Bhati, A. K., Bhattarai, Bichsel, H., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Borowski, W., Bouchet, J., Brandin, A. V., Brovko, S. G., Bruna, E., Bültmann, S., Bunzarov, I., Burton, T. P., Butterworth, J., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Cendejas, R., Cervantes, M. C., Chaloupka, P., Chang, Z., Chattopadhyay, S., Chen, H. F., Chen, J. H., Chen, J. Y., Chen, L., Cheng, J., Cherney, M., Chikanian, A., Christie, W., Chung, P., Chwastowski, J., Codrington, M. J. M., Corliss, R., Cramer, J. G., Crawford, H. J., Cui, X., Das, S., Leyva, A. Davila, De Silva, L. C., Debbe, R. R., Dedovich, T. G., Deng, J., de Souza, R. Derradi, Dhamija, S., di Ruzza, B., Didenko, L., Dilks, Ding, F., Dion, A., Djawotho, P., Dong, X., Drachenberg, J. L., Draper, J. E., Du, C. M., Dunkelberger, L. E., Dunlop, J. C., Efimov, L. G., Elnimr, M., Engelage, J., Engle, K. S., Eppley, G., Eun, L., Evdokimov, O., Fatemi, R., Fazio, S., Fedorisin, J., Fersch, R. G., Filip, P., Finch, E., Fisyak, Y., Flores, C. E., Gagliardi, C. A., Gangadharan, D. R., Garand, D., Geurts, F., Gibson, A., Gliske, S., Grebenyuk, O. G., Grosnick, D., Guo, Y., Gupta, A., Gupta, S., Guryn, W., Haag, B., Hajkova, O., Hamed, A., Han, L-X., Haque, R., Harris, J. W., Hays-Wehle, J. P., Heppelmann, S., Hirsch, A., Hoffmann, G. W., Hofman, D. J., Horvat, S., Huang, B., Huang, H. Z., Huck, P., Humanic, T. J., Igo, G., Jacobs, W. W., Jena, C., Judd, E. G., Kabana, S., Kang, K., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kesich, A., Kikola, D. P., Kiryluk, J., Kisel, I., Kisiel, A., Koetke, D. D., Kollegger, T., Konzer, J., Koralt, I., Korsch, W., Kotchenda, L., Kravtsov, P., Krueger, K., Kulakov, I., Kumar, L., Lamont, M. A. C., Landgraf, J. M., Landry, K. D., LaPointe, S., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Leight, W., LeVine, M. J., Li, C., Li, W., Li, X., Li, Y., Li, Z. M., Lima, L. M., Lisa, M. A., Liu, F., Ljubicic, T., Llope, W. J., Longacre, R. S., Luo, X., Luszczak, A., Ma, G. L., Ma, Y. G., Don, D. M. M. D. Madagodagettige, Mahapatra, D. P., Majka, R., Margetis, S., Markert, C., Masui, H., Matis, H. S., McDonald, D., McShane, T. S., Mioduszewski, S., Mitrovski, M. K., Mohammed, Y., Mohanty, B., Mondal, M. M., Munhoz, M. G., Mustafa, M. K., Naglis, M., Nandi, B. K., Nasim, Md., Nayak, T. K., Nelson, J. M., Nogach, L. V., Novak, J., Odyniec, G., Ogawa, A., Oh, K., Ohlson, A., Okorokov, V., Oldag, E. W., Oliveira, R. A. N., Olson, D., Pachr, M., Page, B. S., Pal, S. K., Pan, Y. X., Pandit, Y., Panebratsev, Y., Pawlak, T., Pawlik, B., Pei, H., Perkins, C., Peryt, W., Pile, P., Planinic, M., Pluta, J., Plyku, D., Poljak, N., Porter, J., Poskanzer, A. M., Powell, C. B., Pruneau, C., Pruthi, N. K., Przybycien, M., Pujahari, P. R., Putschke, J., Qiu, H., Ramachandran, S., Raniwala, R., Raniwala, S., Ray, R. L., Riley, C. K., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ross, J. F., Roy, A., Ruan, L., Rusnak, J., Sahoo, N. R., Sahu, P. K., Sakrejda, I., Salur, S., Sandacz, A., Sandweiss, J., Sangaline, E., Sarkar, A., Schambach, J., Scharenberg, R. P., Schmah, A. M., Schmidke, B., Schmitz, N., Schuster, T. R., Seger, J., Seyboth, P., Shah, N., Shahaliev, E., Shao, M., Sharma, B., Sharma, M., Shen, W. Q., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Singaraju, R. N., Skoby, M. J., Smirnov, D., Smirnov, N., Solanki, D., Sorensen, P., deSouza, U. G., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Stevens, J. R., Stock, R., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Suarez, M. C., Sumbera, M., Sun, X. M., Sun, Y., Sun, Z., Surrow, B., Svirida, D. N., Symons, T. J. M., de Toledo, A. Szanto, Takahashi, J., Tang, A. H., Tang, Z., Tarini, L. H., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Tlusty, D., Tokarev, M., Trentalange, S., Tribble, R. E., Tribedy, P., Trzeciak, B. A., Tsai, O. D., Turnau, J., Ullrich, T., Underwood, D. G., Van Buren, G., van Nieuwenhuizen, G., Vanfossen, Jr., J. A., Varma, R., Vasconcelos, G. M. S., Vertesi, R., Videbæk, F., Viyogi, Y. P., Vokal, S., Voloshin, S. A., Vossen, A., Wada, M., Walker, M., Wang, F., Wang, G., Wang, H., Wang, J. S., Wang, Q., Wang, X. L., Wang, Y., Webb, G., Webb, J. C., Westfall, G. D., Wieman, H., Wissink, S. W., Witt, R., Wu, Y. F., Xiao, Z., Xie, W., Xin, K., Xu, H., Xu, N., Xu, Q. H., Xu, W., Xu, Y., Xu, Z., Yan, Yang, C., Yang, Y., Yepes, P., Yi, L., Yip, K., Yoo, I-K., Zawisza, Y., Zbroszczyk, H., Zha, W., Zhang, J. B., Zhang, S., Zhang, X. P., Zhang, Y., Zhang, Z. P., Zhao, F., Zhao, J., Zhong, C., Zhu, X., Zhu, Y. H., Zoulkarneeva, Y., and Zyzak, M.

Subjects
Nuclear Experiment
Abstract

Measurements of the elliptic flow, $v_{2}$, of identified hadrons ($\pi^{\pm}$, $K^{\pm}$, $K_{s}^{0}$, $p$, $\bar{p}$, $\phi$, $\Lambda$, $\bar{\Lambda}$, $\Xi^{-}$, $\bar{\Xi}^{+}$, $\Omega^{-}$, $\bar{\Omega}^{+}$) in Au+Au collisions at $\sqrt{s_{NN}}=$ 7.7, 11.5, 19.6, 27, 39 and 62.4 GeV are presented. The measurements were done at mid-rapidity using the Time Projection Chamber and the Time-of-Flight detectors of the STAR experiment during the Beam Energy Scan program at RHIC. A significant difference in the $v_{2}$ values for particles and the corresponding anti-particles was observed at all transverse momenta for the first time. The difference increases with decreasing center-of-mass energy, $\sqrt{s_{NN}}$ (or increasing baryon chemical potential, $\mu_{B}$) and is larger for the baryons as compared to the mesons. This implies that particles and anti-particles are no longer consistent with the universal number-of-constituent quark (NCQ) scaling of $v_{2}$ that was observed at $\sqrt{s_{NN}}=$ 200 GeV. However, for the group of particles NCQ scaling at $(m_{T}-m_{0})/n_{q}>$ 0.4 GeV/$c^{2}$ is not violated within $\pm$10%. The $v_{2}$ values for $\phi$ mesons at 7.7 and 11.5 GeV are approximately two standard deviations from the trend defined by the other hadrons at the highest measured $p_{T}$ values.

Published
2013
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35. Third Harmonic Flow of Charged Particles in Au+Au Collisions at sqrtsNN = 200 GeV

Author

STAR Collaboration, Adamczyk, L., Adkins, J. K., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alekseev, I., Alford, J., Anson, C. D., Aparin, A., Arkhipkin, D., Aschenauer, E., Averichev, G. S., Balewski, J., Banerjee, A., Barnovska, Z., Beavis, D. R., Bellwied, R., Betancourt, M. J., Betts, R. R., Bhasin, A., Bhati, A. K., Bichsel, H., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Borowski, W., Bouchet, J., Brandin, A. V., Brovko, S. G., Bruna, E., Bültmann, S., Bunzarov, I., Burton, T. P., Butterworth, J., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Cendejas, R., Cervantes, M. C., Chaloupka, P., Chang, Z., Chattopadhyay, S., Chen, H. F., Chen, J. H., Chen, J. Y., Chen, L., Cheng, J., Cherney, M., Chikanian, A., Christie, W., Chung, P., Chwastowski, J., Codrington, M. J. M., Corliss, R., Cramer, J. G., Crawford, H. J., Cui, X., Das, S., Leyva, A. Davila, De Silva, L. C., Debbe, R. R., Dedovich, T. G., Deng, J., de Souza, R. Derradi, Dhamija, S., di Ruzza, B., Didenko, L., Ding, F., Dion, A., Djawotho, P., Dong, X., Drachenberg, J. L., Draper, J. E., Du, C. M., Dunkelberger, L. E., Dunlop, J. C., Efimov, L. G., Elnimr, M., Engelage, J., Engle, K. S., Eppley, G., Eun, L., Evdokimov, O., Fatemi, R., Fazio, S., Fedorisin, J., Fersch, R. G., Filip, P., Finch, E., Fisyak, Y., Flores, C. E., Gagliardi, C. A., Gangadharan, D. R., Garand, D., Geurts, F., Gibson, A., Gliske, S., Grebenyuk, O. G., Grosnick, D., Guo, Y., Gupta, A., Gupta, S., Guryn, W., Haag, B., Hajkova, O., Hamed, A., Han, L. -X., Haque, R., Harris, J. W., Hays-Wehle, J. P., Heppelmann, S., Hirsch, A., Hoffmann, G. W., Hofman, D. J., Horvat, S., Huang, B., Huang, H. Z., Huck, P., Humanic, T. J., Igo, G., Jacobs, W. W., Jena, C., Judd, E. G., Kabana, S., Kang, K., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kesich, A., Kikola, D. P., Kiryluk, J., Kisel, I., Kisiel, A., Koetke, D. D., Kollegger, T., Konzer, J., Koralt, I., Korsch, W., Kotchenda, L., Kravtsov, P., Krueger, K., Kulakov, I., Kumar, L., Lamont, M. A. C., Landgraf, J. M., Landry, K. D., LaPointe, S., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Leight, W., LeVine, M. J., Li, C., Li, W., Li, X., Li, Y., Li, Z. M., Lima, L. M., Lisa, M. A., Liu, F., Ljubicic, T., Llope, W. J., Longacre, R. S., Luo, X., Luszczak, A., Ma, G. L., Ma, Y. G., Don, D. M. M. D. Madagodagettige, Mahapatra, D. P., Majka, R., Margetis, S., Markert, C., Masui, H., Matis, H. S., McDonald, D., McShane, T. S., Mioduszewski, S., Mitrovski, M. K., Mohammed, Y., Mohanty, B., Mondal, M. M., Munhoz, M. G., Mustafa, M. K., Naglis, M., Nandi, B. K., Nasim, Md., Nayak, T. K., Nelson, J. M., Nogach, L. V., Novak, J., Odyniec, G., Ogawa, A., Oh, K., Ohlson, A., Okorokov, V., Oldag, E. W., Oliveira, R. A. N., Olson, D., Pachr, M., Page, B. S., Pal, S. K., Pan, Y. X., Pandit, Y., Panebratsev, Y., Pawlak, T., Pawlik, B., Pei, H., Perkins, C., Peryt, W., Pile, P., Planinic, M., Pluta, J., Plyku, D., Poljak, N., Porter, J., Poskanzer, A. M., Powell, C. B., Pruneau, C., Pruthi, N. K., Przybycien, M., Pujahari, P. R., Putschke, J., Qiu, H., Ramachandran, S., Raniwala, R., Raniwala, S., Riley, C. K., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ross, J. F., Roy, A., Ruan, L., Rusnak, J., Sahoo, N. R., Sahu, P. K., Sakrejda, I., Salur, S., Sandacz, A., Sandweiss, J., Sangaline, E., Sarkar, A., Schambach, J., Scharenberg, R. P., Schmah, A. M., Schmidke, B., Schmitz, N., Schuster, T. R., Seger, J., Seyboth, P., Shah, N., Shahaliev, E., Shao, M., Sharma, B., Sharma, M., Shen, W. Q., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Singaraju, R. N., Skoby, M. J., Smirnov, D., Smirnov, N., Solanki, D., Sorensen, P., deSouza, U. G., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Stevens, J. R., Stock, R., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Suarez, M. C., Sumbera, M., Sun, X. M., Sun, Y., Sun, Z., Surrow, B., Svirida, D. N., Symons, T. J. M., de Toledo, A. Szanto, Takahashi, J., Tang, A. H., Tang, Z., Tarini, L. H., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Tlusty, D., Tokarev, M., Trentalange, S., Tribble, R. E., Tribedy, P., Trzeciak, B. A., Tsai, O. D., Turnau, J., Ullrich, T., Underwood, D. G., Van Buren, G., van Nieuwenhuizen, G., Vanfossen, Jr., J. A., Varma, R., Vasconcelos, G. M. S., Vertesi, R., Videbæk, F., Viyogi, Y. P., Vokal, S., Voloshin, S. A., Vossen, A., Wada, M., Walker, M., Wang, F., Wang, G., Wang, H., Wang, J. S., Wang, Q., Wang, X. L., Wang, Y., Webb, G., Webb, J. C., Westfall, G. D., Wieman, H., Wissink, S. W., Witt, R., Wu, Y. F., Xiao, Z., Xie, W., Xin, K., Xu, H., Xu, N., Xu, Q. H., Xu, W., Xu, Y., Xu, Z., Yang, C., Yang, Y., Yepes, P., Yi, L., Yip, K., Yoo, I. -K., Zawisza, Y., Zbroszczyk, H., Zha, W., Zhang, J. B., Zhang, S., Zhang, X. P., Zhang, Y., Zhang, Z. P., Zhao, F., Zhao, J., Zhong, C., Zhu, X., Zhu, Y. H., Zoulkarneeva, Y., and Zyzak, M.

Subjects
Nuclear Experiment
Abstract

We report measurements of the third harmonic coefficient of the azimuthal anisotropy, v_3, known as triangular flow. The analysis is for charged particles in Au+Au collisions at sqrtsNN = 200 GeV, based on data from the STAR experiment at the Relativistic Heavy Ion Collider. Two-particle correlations as a function of their pseudorapidity separation are fit with narrow and wide Gaussians. Measurements of triangular flow are extracted from the wide Gaussian, from two-particle cumulants with a pseudorapidity gap, and also from event plane analysis methods with a large pseudorapidity gap between the particles and the event plane. These results are reported as a function of transverse momentum and centrality. A large dependence on the pseudorapidity gap is found. Results are compared with other experiments and model calculations., Comment: 12 pages, 12 figures

Published
2013
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36. Dielectron azimuthal anisotropy at mid-rapidity in Au+Au collisions at sNN =200 GeV

Author

Adamczyk, L, Adkins, JK, Agakishiev, G, Aggarwal, MM, Ahammed, Z, Alekseev, I, Alford, J, Anson, CD, Aparin, A, Arkhipkin, D, Aschenauer, EC, Averichev, GS, Banerjee, A, Beavis, DR, Bellwied, R, Bhasin, A, Bhati, AK, Bhattarai, P, Bichsel, H, Bielcik, J, Bielcikova, J, Bland, LC, Bordyuzhin, IG, Borowski, W, Bouchet, J, Brandin, AV, Brovko, SG, Bültmann, S, Bunzarov, I, Burton, TP, Butterworth, J, Caines, H, Calderón De La Barca Sánchez, M, Cebra, D, Cendejas, R, Cervantes, MC, Chaloupka, P, Chang, Z, Chattopadhyay, S, Chen, HF, Chen, JH, Chen, L, Cheng, J, Cherney, M, Chikanian, A, Christie, W, Chwastowski, J, Codrington, MJM, Contin, G, Cramer, JG, Crawford, HJ, Cui, X, Das, S, Davila Leyva, A, De Silva, LC, Debbe, RR, Dedovich, TG, Deng, J, Derevschikov, AA, Derradi De Souza, R, Dhamija, S, Di Ruzza, B, Didenko, L, Dilks, C, Ding, F, Djawotho, P, Dong, X, Drachenberg, JL, Draper, JE, Du, CM, Dunkelberger, LE, Dunlop, JC, Efimov, LG, Engelage, J, Engle, KS, Eppley, G, Eun, L, Evdokimov, O, Eyser, O, Fatemi, R, Fazio, S, Fedorisin, J, Filip, P, Finch, E, Fisyak, Y, Flores, CE, Gagliardi, CA, Gangadharan, DR, Garand, D, Geurts, F, Gibson, A, Girard, M, Gliske, S, Greiner, L, Grosnick, D, Gunarathne, DS, Guo, Y, Gupta, A, Gupta, S, and Guryn, W

Subjects
nucl-ex, Nuclear & Particles Physics, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Atomic, Molecular, Nuclear, Particle and Plasma Physics
Abstract

We report on the first measurement of the azimuthal anisotropy (v2) of dielectrons (e+e- pairs) at mid-rapidity from sNN=200 GeV Au+Au collisions with the STAR detector at the Relativistic Heavy Ion Collider (RHIC), presented as a function of transverse momentum (pT) for different invariant-mass regions. In the mass region Mee

Published
2014

37. J/ψ polarization in p+p collisions at s=200 GeV in STAR

Author

Adamczyk, L, Adkins, JK, Agakishiev, G, Aggarwal, MM, Ahammed, Z, Alekseev, I, Alford, J, Anson, CD, Aparin, A, Arkhipkin, D, Aschenauer, EC, Averichev, GS, Balewski, J, Banerjee, A, Barnovska, Z, Beavis, DR, Bellwied, R, Bhasin, A, Bhati, AK, Bhattarai, P, Bichsel, H, Bielcik, J, Bielcikova, J, Bland, LC, Bordyuzhin, IG, Borowski, W, Bouchet, J, Brandin, AV, Brovko, SG, Bültmann, S, Bunzarov, I, Burton, TP, Butterworth, J, Caines, H, Calderón De La Barca Sánchez, M, Cebra, D, Cendejas, R, Cervantes, MC, Chaloupka, P, Chang, Z, Chattopadhyay, S, Chen, HF, Chen, JH, Chen, L, Cheng, J, Cherney, M, Chikanian, A, Christie, W, Chwastowski, J, Codrington, MJM, Corliss, R, Cramer, JG, Crawford, HJ, Cui, X, Das, S, Davila Leyva, A, De Silva, LC, Debbe, RR, Dedovich, TG, Deng, J, Derevschikov, AA, Derradi De Souza, R, Dhamija, S, Di Ruzza, B, Didenko, L, Dilks, C, Ding, F, Djawotho, P, Dong, X, Drachenberg, JL, Draper, JE, Du, CM, Dunkelberger, LE, Dunlop, JC, Efimov, LG, Engelage, J, Engle, KS, Eppley, G, Eun, L, Evdokimov, O, Fatemi, R, Fazio, S, Fedorisin, J, Filip, P, Finch, E, Fisyak, Y, Flores, CE, Gagliardi, CA, Gangadharan, DR, Garand, D, Geurts, F, Gibson, A, Girard, M, Gliske, S, Grosnick, D, Guo, Y, Gupta, A, Gupta, S, Guryn, W, and Haag, B

Subjects
Charmonia, Polarization, Spin alignment, STAR, RHIC, nucl-ex, Nuclear & Particles Physics, Mathematical Physics, Astronomical and Space Sciences, Atomic, Molecular, Nuclear, Particle and Plasma Physics
Abstract

We report on a polarization measurement of inclusive J/ψ mesons in the di-electron decay channel at mid-rapidity at 2 < pT < 6 GeV/c in p + p collisions at √s = 200 GeV. Data were taken with the STAR detector at RHIC. The J/ψ polarization measurement should help to distinguish between the different models of the J/ψ production mechanism since they predict different pT dependences of the J/ψ polarization. In this analysis, J/ψ polarization is studied in the helicity frame. The polarization parameter λθ measured at RHIC becomes smaller towards high pT , indicating more longitudinal J/ψ polarization as pT increases. The result is compared with predictions of presently available models.

Published
2014

38. STAR Collaboration

Author

Abdelwahab, NM, Adamczyk, L, Adkins, JK, Agakishiev, G, Aggarwal, MM, Ahammed, Z, Alekseev, I, Alford, J, Aparin, A, Arkhipkin, D, Aschenauer, EC, Averichev, GS, Banerjee, A, Beavis, DR, Bellwied, R, Bhasin, A, Bhati, AK, Bhattarai, P, Bielcik, J, Bielcikova, J, Bland, LC, Bordyuzhin, IG, Borowski, W, Bouchet, J, Brandin, AV, Bültmann, S, Bunzarov, I, Burton, TP, Butterworth, J, Caines, H, Calderón de la Barca Sánchez, M, Campbell, JM, Cebra, D, Cendejas, R, Cervantes, MC, Chaloupka, P, Chang, Z, Chattopadhyay, S, Chen, HF, Chen, JH, Chen, L, Cheng, J, Cherney, M, Christie, W, Chwastowski, J, Codrington, MJM, Contin, G, Cramer, JG, Crawford, HJ, Cui, X, Das, S, Davila Leyva, A, De Silva, LC, Debbe, RR, Dedovich, TG, Deng, J, Derevschikov, AA, Derradi de Souza, R, di Ruzza, B, Didenko, L, Dilks, C, Ding, F, Djawotho, P, Dong, X, Drachenberg, JL, Draper, JE, Du, CM, Dunkelberger, LE, Dunlop, JC, Efimov, LG, Engelage, J, Engle, KS, Eppley, G, Esha, R, Eun, L, Evdokimov, O, Eyser, O, Fatemi, R, Fazio, S, Federic, P, Fedorisin, J, Filip, P, Fisyak, Y, Flores, CE, Gagliardi, CA, Gangadharan, DR, Garand, D, Geurts, F, Gibson, A, Girard, M, Greiner, L, Grosnick, D, Gunarathne, DS, Guo, Y, Gupta, A, Gupta, S, Guryn, W, Hamad, A, Hamed, A, and Han, LX

Subjects
Nuclear & Particles Physics, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Quantum Physics, Astronomical and Space Sciences, Atomic, Molecular, Nuclear, Particle and Plasma Physics
Published
2014

39. Dielectron azimuthal anisotropy at mid-rapidity in Au + Au collisions at sNN=200 GeV

Author

Adamczyk, L, Adkins, JK, Agakishiev, G, Aggarwal, MM, Ahammed, Z, Alekseev, I, Alford, J, Anson, CD, Aparin, A, Arkhipkin, D, Aschenauer, EC, Averichev, GS, Banerjee, A, Beavis, DR, Bellwied, R, Bhasin, A, Bhati, AK, Bhattarai, P, Bichsel, H, Bielcik, J, Bielcikova, J, Bland, LC, Bordyuzhin, IG, Borowski, W, Bouchet, J, Brandin, AV, Brovko, SG, Bültmann, S, Bunzarov, I, Burton, TP, Butterworth, J, Caines, H, de la Barca Sánchez, M Calderón, Cebra, D, Cendejas, R, Cervantes, MC, Chaloupka, P, Chang, Z, Chattopadhyay, S, Chen, HF, Chen, JH, Chen, L, Cheng, J, Cherney, M, Chikanian, A, Christie, W, Chwastowski, J, Codrington, MJM, Contin, G, Cramer, JG, Crawford, HJ, Cui, X, Das, S, Leyva, A Davila, De Silva, LC, Debbe, RR, Dedovich, TG, Deng, J, Derevschikov, AA, de Souza, R Derradi, Dhamija, S, di Ruzza, B, Didenko, L, Dilks, C, Ding, F, Djawotho, P, Dong, X, Drachenberg, JL, Draper, JE, Du, CM, Dunkelberger, LE, Dunlop, JC, Efimov, LG, Engelage, J, Engle, KS, Eppley, G, Eun, L, Evdokimov, O, Eyser, O, Fatemi, R, Fazio, S, Fedorisin, J, Filip, P, Finch, E, Fisyak, Y, Flores, CE, Gagliardi, CA, Gangadharan, DR, Garand, D, Geurts, F, Gibson, A, Girard, M, Gliske, S, Greiner, L, Grosnick, D, Gunarathne, DS, Guo, Y, Gupta, A, Gupta, S, and Guryn, W

Subjects
nucl-ex, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Nuclear & Particles Physics
Abstract

We report on the first measurement of the azimuthal anisotropy (v2) of dielectrons (e+e- pairs) at mid-rapidity from sNN=200 GeV Au+Au collisions with the STAR detector at the Relativistic Heavy Ion Collider (RHIC), presented as a function of transverse momentum (pT) for different invariant-mass regions. In the mass region Mee

Published
2014

40. J/ψ polarization in p+p collisions at s=200 GeV in STAR

Author

Collaboration, STAR, Adamczyk, L, Adkins, JK, Agakishiev, G, Aggarwal, MM, Ahammed, Z, Alekseev, I, Alford, J, Anson, CD, Aparin, A, Arkhipkin, D, Aschenauer, EC, Averichev, GS, Balewski, J, Banerjee, A, Barnovska, Z, Beavis, DR, Bellwied, R, Bhasin, A, Bhati, AK, Bhattarai, P, Bichsel, H, Bielcik, J, Bielcikova, J, Bland, LC, Bordyuzhin, IG, Borowski, W, Bouchet, J, Brandin, AV, Brovko, SG, Bültmann, S, Bunzarov, I, Burton, TP, Butterworth, J, Caines, H, de la Barca Sánchez, M Calderón, Cebra, D, Cendejas, R, Cervantes, MC, Chaloupka, P, Chang, Z, Chattopadhyay, S, Chen, HF, Chen, JH, Chen, L, Cheng, J, Cherney, M, Chikanian, A, Christie, W, Chwastowski, J, Codrington, MJM, Corliss, R, Cramer, JG, Crawford, HJ, Cui, X, Das, S, Leyva, A Davila, De Silva, LC, Debbe, RR, Dedovich, TG, Deng, J, Derevschikov, AA, de Souza, R Derradi, Dhamija, S, di Ruzza, B, Didenko, L, Dilks, C, Ding, F, Djawotho, P, Dong, X, Drachenberg, JL, Draper, JE, Du, CM, Dunkelberger, LE, Dunlop, JC, Efimov, LG, Engelage, J, Engle, KS, Eppley, G, Eun, L, Evdokimov, O, Fatemi, R, Fazio, S, Fedorisin, J, Filip, P, Finch, E, Fisyak, Y, Flores, CE, Gagliardi, CA, Gangadharan, DR, Garand, D, Geurts, F, Gibson, A, Girard, M, Gliske, S, Grosnick, D, Guo, Y, Gupta, A, Gupta, S, and Guryn, W

Subjects
Charmonia, Polarization, Spin alignment, STAR, RHIC, nucl-ex, Mathematical Physics, Astronomical and Space Sciences, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Nuclear & Particles Physics
Abstract

We report on a polarization measurement of inclusive J/ψ mesons in the di-electron decay channel at mid-rapidity at 2 < pT < 6 GeV/c in p + p collisions at √s = 200 GeV. Data were taken with the STAR detector at RHIC. The J/ψ polarization measurement should help to distinguish between the different models of the J/ψ production mechanism since they predict different pT dependences of the J/ψ polarization. In this analysis, J/ψ polarization is studied in the helicity frame. The polarization parameter λθ measured at RHIC becomes smaller towards high pT , indicating more longitudinal J/ψ polarization as pT increases. The result is compared with predictions of presently available models.

Published
2014

41. Single Spin Asymmetry $A_N$ in Polarized Proton-Proton Elastic Scattering at $\sqrt{s}=200$ GeV

Author

STAR Collaboration, Adamczyk, L., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alakhverdyants, A. V., Alekseev, I., Alford, J., Anson, C. D., Arkhipkin, D., Aschenauer, E., Averichev, G. S., Balewski, J., Banerjee, A., Barnovska, Z., Beavis, D. R., Bellwied, R., Betancourt, M. J., Betts, R. R., Bhasin, A., Bhati, A. K., Bichsel, H., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Borowski, W., Bouchet, J., Brandin, A. V., Brovko, S. G., Bruna, E., Bültmann, S., Bunzarov, I., Burton, T. P., Butterworth, J., Cai, X. Z., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Cendejas, R., Cervantes, M. C., Chaloupka, P., Chang, Z., Chattopadhyay, S., Chen, H. F., Chen, J. H., Chen, J. Y., Chen, L., Cheng, J., Cherney, M., Chikanian, A., Christie, W., Chung, P., Chwastowski, J., Codrington, M. J. M., Corliss, R., Cramer, J. G., Crawford, H. J., Cui, X., Das, S., Leyva, A. Davila, De Silva, L. C., Debbe, R. R., Dedovich, T. G., Deng, J., de Souza, R. Derradi, Dhamija, S., Didenko, L., Ding, F., Dion, A., Djawotho, P., Dong, X., Drachenberg, J. L., Draper, J. E., Du, C. M., Dunkelberger, L. E., Dunlop, J. C., Efimov, L. G., Elnimr, M., Engelage, J., Eppley, G., Eun, L., Evdokimov, O., Fatemi, R., Fazio, S., Fedorisin, J., Fersch, R. G., Filip, P., Finch, E., Fisyak, Y., Gagliardi, C. A., Gangadharan, D. R., Geurts, F., Gibson, A., Gliske, S., Gorbunov, Y. N., Grebenyuk, O. G., Grosnick, D., Gupta, S., Guryn, W., Haag, B., Hajkova, O., Hamed, A., Han, L-X., Harris, J. W., Hays-Wehle, J. P., Heppelmann, S., Hirsch, A., Hoffmann, G. W., Hofman, D. J., Horvat, S., Huang, B., Huang, H. Z., Huck, P., Humanic, T. J., Huo, L., Igo, G., Jacobs, W. W., Jena, C., Judd, E. G., Kabana, S., Kang, K., Kapitan, J., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kesich, A., Kikola, D. P., Kiryluk, J., Kisel, I., Kisiel, A., Kizka, V., Klein, S. R., Koetke, D. D., Kollegger, T., Konzer, J., Koralt, I., Koroleva, L., Korsch, W., Kotchenda, L., Kravtsov, P., Krueger, K., Kulakov, I., Kumar, L., Lamont, M. A. C., Landgraf, J. M., LaPointe, S., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Leight, W., LeVine, M. J., Li, C., Li, L., Li, W., Li, X., Li, Y., Li, Z. M., Lima, L. M., Lisa, M. A., Liu, F., Ljubicic, T., Llope, W. J., Longacre, R. S., Lu, Y., Luo, X., Luszczak, A., Ma, G. L., Ma, Y. G., Don, D. M. M. D. Madagodagettige, Mahapatra, D. P., Majka, R., Mall, O. I., Margetis, S., Markert, C., Masui, H., Matis, H. S., McDonald, D., McShane, T. S., Mioduszewski, S., Mitrovski, M. K., Mohammed, Y., Mohanty, B., Mondal, M. M., Morozov, B., Munhoz, M. G., Mustafa, M. K., Naglis, M., Nandi, B. K., Nasim, Md., Nayak, T. K., Nelson, J. M., Nogach, L. V., Novak, J., Odyniec, G., Ogawa, A., Oh, K., Ohlson, A., Okorokov, V., Oldag, E. W., Oliveira, R. A. N., Olson, D., Ostrowski, P., Pachr, M., Page, B. S., Pal, S. K., Pan, Y. X., Pandit, Y., Panebratsev, Y., Pawlak, T., Pawlik, B., Pei, H., Perkins, C., Peryt, W., Pile, P., Planinic, M., Pluta, J., Plyku, D., Poljak, N., Porter, J., Poskanzer, A. M., Powell, C. B., Pruneau, C., Pruthi, N. K., Przybycien, M., Pujahari, P. R., Putschke, J., Qiu, H., Raniwala, R., Raniwala, S., Ray, R. L., Redwine, R., Reed, R., Riley, C. K., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ross, J. F., Ruan, L., Rusnak, J., Sahoo, N. R., Sahu, P. K., Sakrejda, I., Salur, S., Sandacz, A., Sandweiss, J., Sangaline, E., Sarkar, A., Schambach, J., Scharenberg, R. P., Schmah, A. M., Schmidke, B., Schmitz, N., Schuster, T. R., Seele, J., Seger, J., Seyboth, P., Shah, N., Shahaliev, E., Shao, M., Sharma, B., Sharma, M., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Singaraju, R. N., Skoby, M. J., Smirnov, D., Smirnov, N., Solanki, D., Sorensen, P., deSouza, U. G., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Steadman, S. G., Stevens, J. R., Stock, R., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Suarez, M. C., Sumbera, M., Sun, X. M., Sun, Y., Sun, Z., Surrow, B., Svirida, D. N., Symons, T. J. M., de Toledo, A. Szanto, Takahashi, J., Tang, A. H., Tang, Z., Tarini, L. H., Tarnowsky, T., Thein, D., Thomas, J. H., Tian, J., Timmins, A. R., Tlusty, D., Tokarev, M., Trentalange, S., Tribble, R. E., Tribedy, P., Trzeciak, B. A., Tsai, O. D., Turnau, J., Ullrich, T., Underwood, D. G., Van Buren, G., van Nieuwenhuizen, G., Vanfossen, Jr., J. A., Varma, R., Vasconcelos, G. M. S., Videbæk, F., Viyogi, Y. P., Vokal, S., Voloshin, S. A., Vossen, A., Wada, M., Wang, F., Wang, G., Wang, H., Wang, J. S., Wang, Q., Wang, X. L., Wang, Y., Webb, G., Webb, J. C., Westfall, G. D., Whitten Jr., C., Wieman, H., Wissink, S. W., Witt, R., Witzke, W., Wu, Y. F., Xiao, Z., Xie, W., Xin, K., Xu, H., Xu, N., Xu, Q. H., Xu, W., Xu, Y., Xu, Z., Xue, L., Yang, Y., Yepes, P., Yi, Y., Yip, K., Yoo, I-K., Zawisza, M., Zbroszczyk, H., Zhang, J. B., Zhang, S., Zhang, X. P., Zhang, Y., Zhang, Z. P., Zhao, F., Zhao, J., Zhong, C., Zhu, X., Zhu, Y. H., Zoulkarneeva, Y., and Zyzak, M.

Subjects
Nuclear Experiment, High Energy Physics - Experiment
Abstract

We report a high precision measurement of the transverse single spin asymmetry $A_N$ at the center of mass energy $\sqrt{s}=200$ GeV in elastic proton-proton scattering by the STAR experiment at RHIC. The $A_N$ was measured in the four-momentum transfer squared $t$ range $0.003 \leqslant |t| \leqslant 0.035$ $\GeVcSq$, the region of a significant interference between the electromagnetic and hadronic scattering amplitudes. The measured values of $A_N$ and its $t$-dependence are consistent with a vanishing hadronic spin-flip amplitude, thus providing strong constraints on the ratio of the single spin-flip to the non-flip amplitudes. Since the hadronic amplitude is dominated by the Pomeron amplitude at this $\sqrt{s}$, we conclude that this measurement addresses the question about the presence of a hadronic spin flip due to the Pomeron exchange in polarized proton-proton elastic scattering., Comment: 12 pages, 6 figures

Published
2012
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42. Transverse Single-Spin Asymmetry and Cross-Section for pi0 and eta Mesons at Large Feynman-x in Polarized p+p Collisions at sqrt(s)=200 GeV

Author

The STAR Collaboration, Adamczyk, L., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alakhverdyants, A. V., Alekseev, I., Alford, J., Anderson, B. D., Anson, C. D., Arkhipkin, D., Aschenauer, E., Averichev, G. S., Balewski, J., Bannerjee, A., Barnovska, Z., Beavis, D. R., Bellwied, R., Betancourt, M. J., Betts, R. R., Bhasin, A., Bhati, A. K., Bichsel, H., Bielcik, J., Bielcikova, J., Bordyuzhin, I. G., Borowski, W., Bouchet, J., Brandin, A. V., Brovko, S. G., Bruna, E., Bueltmann, S., Bunzarov, I., Burton, T. P., Butterworth, J., Cai, X. Z., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Cendejas, R., Cervantes, M. C., Chaloupka, P., Chattopadhyay, S., Chen, H. F., Chen, J. H., Chen, J. Y., Chen, L., Cheng, J., Cherney, M., Chikanian, A., Christie, W., Chung, P., Chwastowski, J., Codrington, M. J. M., Corliss, R., Cramer, J. G., Crawford, H. J., Cui, X., Leyva, A. Davila, De Silva, L. C., Debbe, R. R., Dedovich, T. G., Deng, J., de Souza, R. Derradi, Dhamija, S., Didenko, L., Ding, F., Dion, A., Djawotho, P., Dong, X., Drachenberg, J. L., Draper, J. E., Du, C. M., Dunkelberger, L. E., Dunlop, J. C., Efimov, L. G., Elnimr, M., Engelage, J., Eppley, G., Eun, L., Evdokimov, O., Fatemi, R., Fazio, S., Fedorisin, J., Fersch, R. G., Filip, P., Finch, E., Fisyak, Y., Gagliardi, C. A., Gangadharan, D. R., Geurts, F., Gliske, S., Gorbunov, Y. N., Grebenyuk, O. G., Grosnick, D., Gupta, S., Guryn, W., Haag, B., Hajkova, O., Hamed, A., Han, L-X., Harris, J. W., Hays-Wehle, J. P., Heppelmann, S., Hirsch, A., Hoffmann, G. W., Hofman, D. J., Horvat, S., Huang, B., Huang, H. Z., Huck, P., Humanic, T. J., Huo, L., Igo, G., Jacobs, W. W., Jena, C., Joseph, J., Judd, E. G., Kabana, S., Kang, K., Kapitan, J., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kesich, A., Kettler, D., Kikola, D. P., Kiryluk, J., Kisiel, A., Kizka, V., Klein, S. R., Koetke, D. D., Kollegger, T., Konzer, J., Koralt, I., Koroleva, L., Korsch, W., Kotchenda, L., Kravtsov, P., Krueger, K., Kumar, L., Lamont, M. A. C., Landgraf, J. M., LaPointe, S., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Leight, W., LeVine, M. J., Li, C., Li, L., Li, W., Li, X., Li, Y., Li, Z. M., Lima, L. M., Lisa, M. A., Liu, F., Ljubicic, T., Llope, W. J., Longacre, R. S., Lu, Y., Luo, X., Luszczak, A., Ma, G. L., Ma, Y. G., Don, D. M. M. D. Madagodagettige, Mahapatra, D. P., Majka, R., Mall, O. I., Margetis, S., Markert, C., Masui, H., Matis, H. S., McDonald, D., McShane, T. S., Mioduszewski, S., Mitrovski, M. K., Mohammed, Y., Mohanty, B., Morozov, B., Munhoz, M. G., Mustafa, M. K., Naglis, M., Nandi, B. K., Nasim, Md., Nayak, T. K., Nogach, L. V., Novak, J., Odyniec, G., Ogawa, A., Oh, K., Ohlson, A., Okorokov, V., Oldag, E. W., Oliveira, R. A. N., Olson, D., Ostrowski, P., Pachr, M., Page, B. S., Pal, S. K., Pan, Y. X., Pandit, Y., Panebratsev, Y., Pawlak, T., Pawlik, B., Pei, H., Perkins, C., Peryt, W., Pile, P., Planinic, M., Pluta, J., Plyku, D., Poljak, N., Porter, J., Poskanzer, A. M., Powell, C. B., Prindle, D., Pruneau, C., Pruthi, N. K., Przybycien, M., Pujahari, P. R., Putschke, J., Qiu, H., Raniwala, R., Raniwala, S., Ray, R. L., Redwine, R., Reed, R., Riley, C. K., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ross, J. F., Ruan, L., Rusnak, J., Sahoo, N. R., Sakrejda, I., Salur, S., Sandacz, A., Sandweiss, J., Sangaline, E., Sarkar, A., Schambach, J., Scharenberg, R. P., Schmah, A. M., Schmidke, B., Schmitz, N., Schuster, T. R., Seele, J., Seger, J., Seyboth, P., Shah, N., Shahaliev, E., Shao, M., Sharma, B., Sharma, M., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Singaraju, R. N., Skoby, M. J., Smirnov, D., Smirnov, N., Solanki, D., Sorensen, P., deSouza, U. G., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Steadman, S. G., Stevens, J. R., Stock, R., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Suarez, M. C., Sumbera, M., Sun, X. M., Sun, Y., Sun, Z., Surrow, B., Svirida, D. N., Symons, T. J. M., de Toledo, A. Szanto, Takahashi, J., Tang, A. H., Tang, Z., Tarini, L. H., Tarnowsky, T., Thein, D., Thomas, J. H., Tian, J., Timmins, A. R., Tlusty, D., Tokarev, M., Trainor, T. A., Trentalange, S., Tribble, R. E., Tribedy, P., Trzeciak, B. A., Tsai, O. D., Turnau, J., Ullrich, T., Underwood, D. G., Van Buren, G., van Nieuwenhuizen, G., Vanfossen, Jr., J. A., Varma, R., Vasconcelos, G. M. S., Videbaek, F., Viyogi, Y. P., Vokal, S., Voloshin, S. A., Vossen, A., Wada, M., Wang, F., Wang, G., Wang, H., Wang, J. S., Wang, Q., Wang, X. L., Wang, Y., Webb, G., Webb, J. C., Westfall, G. D., Whitten Jr, C., Wieman, H., Wissink, S. W., Witt, R., Witzke, W., Wu, Y. F., Xiao, Z., Xie, W., Xin, K., Xu, H., Xu, N., Xu, Q. H., Xu, W., Xu, Y., Xu, Z., Xue, L., Yang, Y., Yepes, P., Yi, Y., Yip, K., Yoo, I-K., Zawisza, M., Zbroszczyk, H., Zhang, J. B., Zhang, S., Zhang, W. M., Zhang, X. P., Zhang, Y., Zhang, Z. P., Zhao, F., Zhao, J., Zhong, C., Zhu, X., Zhu, Y. H., and Zoulkarneeva, Y.

Subjects
Nuclear Experiment, High Energy Physics - Experiment
Abstract

Measurements of the differential cross-section and the transverse single-spin asymmetry, A_N, vs. x_F for pi0 and eta mesons are reported for 0.4 < x_F < 0.75 at an average pseudorapidity of 3.68. A data sample of approximately 6.3 pb^{-1} was analyzed, which was recorded during p+p collisions at sqrt{s} = 200 GeV by the STAR experiment at RHIC. The average transverse beam polarization was 56%. The cross-section for pi0 is consistent with a perturbative QCD prediction, and the eta/pi0 cross-section ratio agrees with previous mid-rapidity measurements. For 0.55 < x_F < 0.75, A_N for eta (0.210 +- 0.056) is 2.2 standard deviations larger than A_N for pi0 (0.081 +- 0.016)., Comment: 7 pages, 5 figures, Submitted to Phys. Rev. D R.C

Published
2012
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43. Longitudinal and transverse spin asymmetries for inclusive jet production at mid-rapidity in polarized p+p collisions at sqrt{s}=200 GeV

Author

The STAR Collaboration, Adamczyk, L., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alakhverdyants, A. V., Alekseev, I., Alford, J., Anderson, B. D., Anson, C. D., Arkhipkin, D., Aschenauer, E., Averichev, G. S., Balewski, J., Banerjee, A., Barnovska, Z., Beavis, D. R., Bellwied, R., Betancourt, M. J., Betts, R. R., Bhasin, A., Bhati, A. K., Bichsel, H., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Borowski, W., Bouchet, J., Brandin, A. V., Bridgeman, A., Brovko, S. G., Bruna, E., Bueltmann, S., Bunzarov, I., Burton, T. P., Butterworth, J., Cai, X. Z., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Cendejas, R., Cervantes, M. C., Chaloupka, P., Chattopadhyay, S., Chen, H. F., Chen, J. H., Chen, J. Y., Chen, L., Cheng, J., Cherney, M., Chikanian, A., Christie, W., Chung, P., Chwastowski, J., Codrington, M. J. M., Corliss, R., Cramer, J. G., Crawford, H. J., Cui, X., Leyva, A. Davila, De Silva, L. C., Debbe, R. R., Dedovich, T. G., Deng, J., de Souza, R. Derradi, Dhamija, S., Didenko, L., Ding, F., Dion, A., Djawotho, P., Dong, X., Drachenberg, J. L., Draper, J. E., Du, C. M., Dunkelberger, L. E., Dunlop, J. C., Efimov, L. G., Elnimr, M., Engelage, J., Eppley, G., Eun, L., Evdokimov, O., Fatemi, R., Fazio, S., Fedorisin, J., Fersch, R. G., Filip, P., Finch, E., Fisyak, Y., Gagliardi, C. A., Gangadharan, D. R., Geurts, F., Gliske, S., Gorbunov, Y. N., Grebenyuk, O. G., Grosnick, D., Gupta, S., Guryn, W., Haag, B., Hajkova, O., Hamed, A., Han, L-X., Harris, J. W., Hays-Wehle, J. P., Heppelmann, S., Hirsch, A., Hoffmann, G. W., Hofman, D. J., Horvat, S., Huang, B., Huang, H. Z., Huck, P., Humanic, T. J., Huo, L., Igo, G., Jacobs, W. W., Jena, C., Joseph, J., Judd, E. G., Kabana, S., Kang, K., Kapitan, J., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kesich, A., Kettler, D., Kikola, D. P., Kiryluk, J., Kisiel, A., Kizka, V., Klein, S. R., Koetke, D. D., Kollegger, T., Konzer, J., Koralt, I., Koroleva, L., Korsch, W., Kotchenda, L., Kowalik, K., Kravtsov, P., Krueger, K., Kumar, L., Lamont, M. A. C., Landgraf, J. M., LaPointe, S., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Leight, W., LeVine, M. J., Li, C., Li, L., Li, W., Li, X., Li, Y., Li, Z. M., Lima, L. M., Lisa, M. A., Liu, F., Ljubicic, T., Llope, W. J., Longacre, R. S., Lu, Y., Luo, X., Luszczak, A., Ma, G. L., Ma, Y. G., Don, D. M. M. D. Madagodagettige, Mahapatra, D. P., Majka, R., Mall, O. I., Margetis, S., Markert, C., Masui, H., Matis, H. S., McDonald, D., McShane, T. S., Millane, J., Mioduszewski, S., Mitrovski, M. K., Mohammed, Y., Mohanty, B., Mondal, M. M., Morozov, B., Munhoz, M. G., Mustafa, M. K., Naglis, M., Nandi, B. K., Nasim, Md., Nayak, T. K., Nogach, L. V., Novak, J., Odyniec, G., Ogawa, A., Oh, K., Ohlson, A., Okorokov, V., Oldag, E. W., Oliveira, R. A. N., Olson, D., Ostrowski, P., Pachr, M., Page, B. S., Pal, S. K., Pan, Y. X., Pandit, Y., Panebratsev, Y., Pawlak, T., Pawlik, B., Pei, H., Perkins, C., Peryt, W., Pile, P., Planinic, M., Pluta, J., Plyku, D., Poljak, N., Porter, J., Poskanzer, A. M., Powell, C. B., Prindle, D., Pruneau, C., Pruthi, N. K., Przybycien, M., Pujahari, P. R., Putschke, J., Qiu, H., Raniwala, R., Raniwala, S., Ray, R. L., Redwine, R., Reed, R., Riley, C. K., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ross, J. F., Ruan, L., Rusnak, J., Sahoo, N. R., Sakrejda, I., Sakuma, T., Salur, S., Sandacz, A., Sandweiss, J., Sangaline, E., Sarkar, A., Sarsour, M., Schambach, J., Scharenberg, R. P., Schmah, A. M., Schmidke, B., Schmitz, N., Schuster, T. R., Seele, J., Seger, J., Seyboth, P., Shah, N., Shahaliev, E., Shao, M., Sharma, B., Sharma, M., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Singaraju, R. N., Skoby, M. J., Smirnov, D., Smirnov, N., Solanki, D., Sorensen, P., deSouza, U. G., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Staszak, D., Steadman, S. G., Stevens, J. R., Stock, R., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Suarez, M. C., Sumbera, M., Sun, X. M., Sun, Y., Sun, Z., Surrow, B., Svirida, D. N., Symons, T. J. M., de Toledo, A. Szanto, Takahashi, J., Tang, A. H., Tang, Z., Tarini, L. H., Tarnowsky, T., Thein, D., Thomas, J. H., Tian, J., Timmins, A. R., Tlusty, D., Tokarev, M., Trainor, T. A., Trentalange, S., Tribble, R. E., Tribedy, P., Trzeciak, B. A., Tsai, O. D., Turnau, J., Ullrich, T., Underwood, D. G., Van Buren, G., van Nieuwenhuizen, G., Vanfossen, Jr., J. A., Varma, R., Vasconcelos, G. M. S., Videbæk, F., Viyogi, Y. P., Vokal, S., Voloshin, S. A., Vossen, A., Wada, M., Wang, F., Wang, G., Wang, H., Wang, J. S., Wang, Q., Wang, X. L., Wang, Y., Webb, G., Webb, J. C., Westfall, G. D., Whitten Jr., C., Wieman, H., Wissink, S. W., Witt, R., Witzke, W., Wu, Y. F., Xiao, Z., Xie, W., Xin, K., Xu, H., Xu, N., Xu, Q. H., Xu, W., Xu, Y., Xu, Z., Xue, L., Yang, Y., Yepes, P., Yi, Y., Yip, K., Yoo, I-K., Zawisza, M., Zbroszczyk, H., Zhang, J. B., Zhang, S., Zhang, W. M., Zhang, X. P., Zhang, Y., Zhang, Z. P., Zhao, F., Zhao, J., Zhong, C., Zhu, X., Zhu, Y. H., and Zoulkarneeva, Y.

Subjects
Nuclear Experiment
Abstract

We report STAR measurements of the longitudinal double-spin asymmetry A_LL, the transverse single-spin asymmetry A_N, and the transverse double-spin asymmetries A_Sigma and A_TT for inclusive jet production at mid-rapidity in polarized p+p collisions at a center-of-mass energy of sqrt{s} = 200 GeV. The data represent integrated luminosities of 7.6 /pb with longitudinal polarization and 1.8 /pb with transverse polarization, with 50-55% beam polarization, and were recorded in 2005 and 2006. No evidence is found for the existence of statistically significant jet A_N, A_Sigma, or A_TT at mid-rapidity. Recent model calculations indicate the A_N results may provide new limits on the gluon Sivers distribution in the proton. The asymmetry A_LL significantly improves the knowledge of gluon polarization in the nucleon., Comment: 18 pages, 16 figures, 8 tables

Published
2012

44. Measurements of $D^{0}$ and $D^{*}$ Production in $p$ + $p$ Collisions at $\sqrt{s}$ = 200 GeV

Author

STAR Collaboration, Adamczyk, L., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alakhverdyants, A. V., Alekseev, I., Alford, J., Anderson, B. D., Anson, C. D., Arkhipkin, D., Aschenauer, E., Averichev, G. S., Balewski, J., Banerjee, A., Barnovska, Z., Beavis, D. R., Bellwied, R., Betancourt, M. J., Betts, R. R., Bhasin, A., Bhati, A. K., Bichsel, H., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Borowski, W., Bouchet, J., Brandin, A. V., Brovko, S. G., Bruna, E., Bültmann, S., Bunzarov, I., Burton, T. P., Butterworth, J., Cai, X. Z., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Cendejas, R., Cervantes, M. C., Chaloupka, P., Chang, Z., Chattopadhyay, S., Chen, H. F., Chen, J. H., Chen, J. Y., Chen, L., Cheng, J., Cherney, M., Chikanian, A., Christie, W., Chung, P., Chwastowski, J., Codrington, M. J. M., Corliss, R., Cramer, J. G., Crawford, H. J., Cui, X., Leyva, A. Davila, De Silva, L. C., Debbe, R. R., Dedovich, T. G., Deng, J., de Souza, R. Derradi, Dhamija, S., Didenko, L., Ding, F., Dion, A., Djawotho, P., Dong, X., Drachenberg, J. L., Draper, J. E., Du, C. M., Dunkelberger, L. E., Dunlop, J. C., Efimov, L. G., Elnimr, M., Engelage, J., Eppley, G., Eun, L., Evdokimov, O., Fatemi, R., Fazio, S., Fedorisin, J., Fersch, R. G., Filip, P., Finch, E., Fisyak, Y., Gagliardi, C. A., Gangadharan, D. R., Geurts, F., Gibson, A., Gliske, S., Gorbunov, Y. N., Grebenyuk, O. G., Grosnick, D., Gupta, S., Guryn, W., Haag, B., Hajkova, O., Hamed, A., Han, L-X., Harris, J. W., Hays-Wehle, J. P., Heppelmann, S., Hirsch, A., Hoffmann, G. W., Hofman, D. J., Horvat, S., Huang, B., Huang, H. Z., Huck, P., Humanic, T. J., Huo, L., Igo, G., Jacobs, W. W., Jena, C., Joseph, J., Judd, E. G., Kabana, S., Kang, K., Kapitan, J., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kesich, A., Kettler, D., Kikola, D. P., Kiryluk, J., Kisel, I., Kisiel, A., Kizka, V., Klein, S. R., Koetke, D. D., Kollegger, T., Konzer, J., Koralt, I., Koroleva, L., Korsch, W., Kotchenda, L., Kravtsov, P., Krueger, K., Kumar, L., Lamont, M. A. C., Landgraf, J. M., LaPointe, S., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Leight, W., LeVine, M. J., Li, C., Li, L., Li, W., Li, X., Li, Y., Li, Z. M., Lima, L. M., Lisa, M. A., Liu, F., Ljubicic, T., Llope, W. J., Longacre, R. S., Lu, Y., Luo, X., Luszczak, A., Ma, G. L., Ma, Y. G., Don, D. M. M. D. Madagodagettige, Mahapatra, D. P., Majka, R., Mall, O. I., Margetis, S., Markert, C., Masui, H., Matis, H. S., McDonald, D., McShane, T. S., Mioduszewski, S., Mitrovski, M. K., Mohammed, Y., Mohanty, B., Mondal, M. M., Morozov, B., Munhoz, M. G., Mustafa, M. K., Naglis, M., Nandi, B. K., Nasim, Md., Nayak, T. K., Nelson, J. M., Nogach, L. V., Novak, J., Odyniec, G., Ogawa, A., Oh, K., Ohlson, A., Okorokov, V., Oldag, E. W., Oliveira, R. A. N., Olson, D., Ostrowski, P., Pachr, M., Page, B. S., Pal, S. K., Pan, Y. X., Pandit, Y., Panebratsev, Y., Pawlak, T., Pawlik, B., Pei, H., Perkins, C., Peryt, W., Pile, P., Planinic, M., Pluta, J., Plyku, D., Poljak, N., Porter, J., Poskanzer, A. M., Powell, C. B., Prindle, D., Pruneau, C., Pruthi, N. K., Przybycien, M., Pujahari, P. R., Putschke, J., Qiu, H., Raniwala, R., Raniwala, S., Ray, R. L., Redwine, R., Reed, R., Riley, C. K., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ross, J. F., Ruan, L., Rusnak, J., Sahoo, N. R., Sakrejda, I., Salur, S., Sandacz, A., Sandweiss, J., Sangaline, E., Sarkar, A., Schambach, J., Scharenberg, R. P., Schmah, A. M., Schmidke, B., Schmitz, N., Schuster, T. R., Seele, J., Seger, J., Seyboth, P., Shah, N., Shahaliev, E., Shao, M., Sharma, B., Sharma, M., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Singaraju, R. N., Skoby, M. J., Smirnov, D., Smirnov, N., Solanki, D., Sorensen, P., deSouza, U. G., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Steadman, S. G., Stevens, J. R., Stock, R., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Suarez, M. C., Sumbera, M., Sun, X. M., Sun, Y., Sun, Z., Surrow, B., Svirida, D. N., Symons, T. J. M., de Toledo, A. Szanto, Takahashi, J., Tang, A. H., Tang, Z., Tarini, L. H., Tarnowsky, T., Thein, D., Thomas, J. H., Tian, J., Timmins, A. R., Tlusty, D., Tokarev, M., Trainor, T. A., Trentalange, S., Tribble, R. E., Tribedy, P., Trzeciak, B. A., Tsai, O. D., Turnau, J., Ullrich, T., Underwood, D. G., Van Buren, G., van Nieuwenhuizen, G., Vanfossen, Jr., J. A., Varma, R., Vasconcelos, G. M. S., Videbæk, F., Viyogi, Y. P., Vokal, S., Voloshin, S. A., Vossen, A., Wada, M., Wang, F., Wang, G., Wang, H., Wang, J. S., Wang, Q., Wang, X. L., Wang, Y., Webb, G., Webb, J. C., Westfall, G. D., Whitten Jr., C., Wieman, H., Wissink, S. W., Witt, R., Witzke, W., Wu, Y. F., Xiao, Z., Xie, W., Xin, K., Xu, H., Xu, N., Xu, Q. H., Xu, W., Xu, Y., Xu, Z., Xue, L., Yang, Y., Yepes, P., Yi, Y., Yip, K., Yoo, I-K., Zawisza, M., Zbroszczyk, H., Zhang, J. B., Zhang, S., Zhang, W. M., Zhang, X. P., Zhang, Y., Zhang, Z. P., Zhao, F., Zhao, J., Zhong, C., Zhu, X., Zhu, Y. H., Zoulkarneeva, Y., and Zyzak, M.

Subjects
Nuclear Experiment
Abstract

We report measurements of charmed-hadron ($D^{0}$, $D^{*}$) production cross sections at mid-rapidity in $p$ + $p$ collisions at a center-of-mass energy of 200 GeV by the STAR experiment. Charmed hadrons were reconstructed via the hadronic decays $D^{0}\rightarrow K^{-}\pi^{+}$, $D^{*+}\rightarrow D^{0}\pi^{+}\rightarrow K^{-}\pi^{+}\pi^{+}$ and their charge conjugates, covering the $p_T$ range of 0.6$-$2.0 GeV/$c$ and 2.0$-$6.0 GeV/$c$ for $D^{0}$ and $D^{*+}$, respectively. From this analysis, the charm-pair production cross section at mid-rapidity is $d\sigma/dy|_{y=0}^{c\bar{c}}$ = 170 $\pm$ 45 (stat.) $^{+38}_{-59}$ (sys.) $\mu$b. The extracted charm-pair cross section is compared to perturbative QCD calculations. The transverse momentum differential cross section is found to be consistent with the upper bound of a Fixed-Order Next-to-Leading Logarithm calculation., Comment: 15 pages, 16 figures. Revised version submitted to Phys. Rev. D

Published
2012
Full Text
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45. Di-electron spectrum at mid-rapidity in $p+p$ collisions at $\sqrt{s} = 200$ GeV

Author

Adamczyk, L., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alakhverdyants, A. V., Alekseev, I., Alford, J., Anderson, B. D., Anson, C. D., Arkhipkin, D., Aschenauer, E., Averichev, G. S., Balewski, J., Banerjee, A., Barnovska, Z., Beavis, D. R., Bellwied, R., Betancourt, M. J., Betts, R. R., Bhasin, A., Bhati, A. K., Bichsel, H., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Borowski, W., Bouchet, J., Brandin, A. V., Brovko, S. G., Bruna, E., Bueltmann, S., Bunzarov, I., Burton, T. P., Butterworth, J., Cai, X. Z., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Cendejas, R., Cervantes, M. C., Chaloupka, P., Chang, Z., Chattopadhyay, S., Chen, H. F., Chen, J. H., Chen, J. Y., Chen, L., Cheng, J., Cherney, M., Chikanian, A., Christie, W., Chung, P., Chwastowski, J., Codrington, M. J. M., Corliss, R., Cramer, J. G., Crawford, H. J., Cui, X., Leyva, A. Davila, De Silva, L. C., Debbe, R. R., Dedovich, T. G., Deng, J., de Souza, R. Derradi, Dhamija, S., Didenko, L., Ding, F., Dion, A., Djawotho, P., Dong, X., Drachenberg, J. L., Draper, J. E., Du, C. M., Dunkelberger, L. E., Dunlop, J. C., Efimov, L. G., Elnimr, M., Engelage, J., Eppley, G., Eun, L., Evdokimov, O., Fatemi, R., Fazio, S., Fedorisin, J., Fersch, R. G., Filip, P., Finch, E., Fisyak, Y., Gagliardi, C. A., Gangadharan, D. R., Geurts, F., Gibson, A., Gliske, S., Gorbunov, Y. N., Grebenyuk, O. G., Grosnick, D., Gupta, S., Guryn, W., Haag, B., Hajkova, O., Hamed, A., Han, L-X., Harris, J. W., Hays-Wehle, J. P., Heppelmann, S., Hirsch, A., Hoffmann, G. W., Hofman, D. J., Horvat, S., Huang, B., Huang, H. Z., Huck, P., Humanic, T. J., Huo, L., Igo, G., Jacobs, W. W., Jena, C., Joseph, J., Judd, E. G., Kabana, S., Kang, K., Kapitan, J., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kesich, A., Kettler, D., Kikola, D. P., Kiryluk, J., Kisel, I., Kisiel, A., Kizka, V., Klein, S. R., Koetke, D. D., Kollegger, T., Konzer, J., Koralt, I., Koroleva, L., Korsch, W., Kotchenda, L., Kravtsov, P., Krueger, K., Kulakov, Kumar, L., Lamont, M. A. C., Landgraf, J. M., LaPointe, S., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Leight, W., LeVine, M. J., Li, C., Li, L., Li, W., Li, X., Li, Y., Li, Z. M., Lima, L. M., Lisa, M. A., Liu, F., Ljubicic, T., Llope, W. J., Longacre, R. S., Lu, Y., Luo, X., Luszczak, A., Ma, G. L., Ma, Y. G., Don, D. M. M. D. Madagodagettige, Mahapatra, D. P., Majka, R., Mall, O. I., Margetis, S., Markert, C., Masui, H., Matis, H. S., McDonald, D., McShane, T. S., Mioduszewski, S., Mitrovski, M. K., Mohammed, Y., Mohanty, B., Mondal, M. M., Morozov, B., Munhoz, M. G., Mustafa, M. K., Naglis, M., Nandi, B. K., Nasim, Md., Nayak, T. K., Nelson, J. M., Nogach, L. V., Novak, J., Odyniec, G., Ogawa, A., Oh, K., Ohlson, A., Okorokov, V., Oldag, E. W., Oliveira, R. A. N., Olson, D., Ostrowski, P., Pachr, M., Page, B. S., Pal, S. K., Pan, Y. X., Pandit, Y., Panebratsev, Y., Pawlak, T., Pawlik, B., Pei, H., Perkins, C., Peryt, W., Pile, P., Planinic, M., Pluta, J., Plyku, D., Poljak, N., Porter, J., Poskanzer, A. M., Powell, C. B., Prindle, D., Pruneau, C., Pruthi, N. K., Przybycien, M., Pujahari, P. R., Putschke, J., Qiu, H., Raniwala, R., Raniwala, S., Ray, R. L., Redwine, R., Reed, R., Riley, C. K., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ross, J. F., Ruan, L., Rusnak, J., Sahoo, N. R., Sakrejda, I., Salur, S., Sandacz, A., Sandweiss, J., Sangaline, E., Sarkar, A., Schambach, J., Scharenberg, R. P., Schmah, A. M., Schmidke, B., Schmitz, N., Schuster, T. R., Seele, J., Seger, J., Seyboth, P., Shah, N., Shahaliev, E., Shao, M., Sharma, B., Sharma, M., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Singaraju, R. N., Skoby, M. J., Smirnov, D., Smirnov, N., Solanki, D., Sorensen, P., deSouza, U. G., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Steadman, S. G., Stevens, J. R., Stock, R., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Suarez, M. C., Sumbera, M., Sun, X. M., Sun, Y., Sun, Z., Surrow, B., Svirida, D. N., Symons, T. J. M., de Toledo, A. Szanto, Takahashi, J., Tang, A. H., Tang, Z., Tarini, L. H., Tarnowsky, T., Thein, D., Thomas, J. H., Tian, J., Timmins, A. R., Tlusty, D., Tokarev, M., Trainor, T. A., Trentalange, S., Tribble, R. E., Tribedy, P., Trzeciak, B. A., Tsai, O. D., Turnau, J., Ullrich, T., Underwood, D. G., Van Buren, G., van Nieuwenhuizen, G., Vanfossen, Jr., J. A., Varma, R., Vasconcelos, G. M. S., Videbæk, F., Viyogi, Y. P., Vokal, S., Voloshin, S. A., Vossen, A., Wada, M., Wang, F., Wang, G., Wang, H., Wang, J. S., Wang, Q., Wang, X. L., Wang, Y., Webb, G., Webb, J. C., Westfall, G. D., Whitten Jr., C., Wieman, H., Wissink, S. W., Witt, R., Witzke, W., Wu, Y. F., Xiao, Z., Xie, W., Xin, K., Xu, H., Xu, N., Xu, Q. H., Xu, W., Xu, Y., Xu, Z., Xue, L., Yang, Y., Yepes, P., Yi, Y., Yip, K., Yoo, I-K., Zawisza, M., Zbroszczyk, H., Zhang, J. B., Zhang, S., Zhang, W. M., Zhang, X. P., Zhang, Y., Zhang, Z. P., Zhao, F., Zhao, J., Zhong, C., Zhu, X., Zhu, Y. H., Zoulkarneeva, Y., and Zyzak, M.

Subjects
Nuclear Experiment
Abstract

We report on mid-rapidity mass spectrum of di-electrons and cross sections of pseudoscalar and vector mesons via $e^{+}e^{-}$ decays, from $\sqrt{s} = 200$ GeV $p+p$ collisions, measured by the large acceptance experiment STAR at RHIC. The ratio of the di-electron continuum to the combinatorial background is larger than 10% over the entire mass range. Simulations of di-electrons from light-meson decays and heavy-flavor decays (charmonium and open charm correlation) are found to describe the data. The extracted $\omega\rightarrow e^{+}e^{-}$ invariant yields are consistent with previous measurements. The mid-rapidity yields ($dN/dy$) of $\phi$ and $J/\psi$ are extracted through their di-electron decay channels and are consistent with the previous measurements of $\phi\rightarrow K^{+}K^{-}$ and $J/\psi\rightarrow e^{+}e^{-}$. Our results suggest a new upper limit of the branching ratio of the $\eta \rightarrow e^{+}e^{-}$ of $1.7\times10^{-5}$ at 90% confidence level., Comment: 15 pages, 17 figures, 4 tables. Published

Published
2012
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46. Measurement of the $W \to e \nu$ and $Z/\gamma^* \to e^+e^-$ Production Cross Sections at Mid-rapidity in Proton-Proton Collisions at $\sqrt{s}$ = 500 GeV

Author

STAR Collaboration, Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alakhverdyants, A. V., Alekseev, I., Alford, J., Anderson, B. D., Anson, C. D., Arkhipkin, D., Averichev, G. S., Balewski, J., Banerjee, Barnovska, Z., Beavis, D. R., Bellwied, R., Betancourt, M. J., Betts, R. R., Bhasin, A., Bhati, A. K., Bichsel, H., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Borowski, W., Bouchet, J., Brandin, A. V., Brovko, S. G., Bruna, E., Bueltmann, S., Bunzarov, I., Burton, T. P., Butterworth, J., Cai, X. Z., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Cendejas, R., Cervantes, M. C., Chaloupka, P., Chattopadhyay, S., Chen, H. F., Chen, J. H., Chen, J. Y., Chen, L., Cheng, J., Cherney, M., Chikanian, A., Christie, W., Chung, P., Codrington, M. J. M., Corliss, R., Cramer, J. G., Crawford, H. J., Cui, X., Leyva, A. Davila, De Silva, L. C., Debbe, R. R., Dedovich, T. G., Deng, J., de Souza, R. Derradi, Dhamija, S., Didenko, L., Ding, F., Djawotho, P., Dong, X., Drachenberg, J. L., Draper, J. E., Du, C. M., Dunkelberger, L. E., Dunlop, J. C., Efimov, L. G., Elnimr, M., Engelage, J., Eppley, G., Eun, L., Evdokimov, O., Fatemi, R., Fedorisin, J., Fersch, R. G., Filip, P., Finch, E., Fisyak, Y., Gagliardi, C. A., Gangadharan, D. R., Geurts, F., Gliske, S., Gorbunov, Y. N., Grebenyuk, O. G., Grosnick, D., Gupta, S., Guryn, W., Haag, B., Hajkova, O., Hamed, A., Han, L-X., Harris, J. W., Hays-Wehle, J. P., Heppelmann, S., Hirsch, A., Hoffmann, G. W., Hofman, D. J., Horvat, S., Huang, B., Huang, H. Z., Huck, P., Humanic, T. J., Huo, L., Igo, G., Jacobs, W. W., Jena, C., Joseph, J., Judd, E. G., Kabana, S., Kang, K., Kapitan, J., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kesich, A., Kettler, D., Kikola, D. P., Kiryluk, J., Kisiel, A., Kizka, V., Klein, S. R., Koetke, D. D., Kollegger, T., Konzer, J., Koralt, I., Koroleva, L., Korsch, W., Kotchenda, L., Kravtsov, P., Krueger, K., Kumar, L., Lamont, M. A. C., Landgraf, J. M., LaPointe, S., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Leight, W., LeVine, M. J., Li, C., Li, L., Li, W., Li, X., Li, Y., Li, Z. M., Lima, L. M., Lisa, M. A., Liu, F., Ljubicic, T., Llope, W. J., Longacre, R. S., Lu, Y., Luo, X., Ma, G. L., Ma, Y. G., Mahapatra, D. P., Majka, R., Mall, O. I., Margetis, S., Markert, C., Masui, H., Matis, H. S., McDonald, D., McShane, T. S., Mioduszewski, S., Mitrovski, M. K., Mohammed, Y., Mohanty, B., Morozov, B., Munhoz, M. G., Mustafa, M. K., Naglis, M., Nandi, B. K., Nasim, Md., Nayak, T. K., Nogach, L. V., Odyniec, G., Ogawa, A., Oh, K., Ohlson, A., Okorokov, V., Oldag, E. W., Oliveira, R. A. N., Olson, D., Pachr, M., Page, B. S., Pal, S. K., Pan, Pandit, Y., Panebratsev, Y., Pawlak, T., Pei, H., Perkins, C., Peryt, W., Pile, P., Planinic, M., Pluta, J., Plyku, D., Poljak, N., Porter, J., Poskanzer, A. M., Powell, C. B., Prindle, D., Pruneau, C., Pruthi, N. K., Pujahari, P. R., Putschke, J., Qiu, H., Raniwala, R., Raniwala, S., Ray, R. L., Redwine, R., Reed, R., Riley, C. K., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ruan, L., Rusnak, J., Sahoo, N. R., Sakrejda, I., Salur, S., Sandweiss, J., Sangaline, E., Sarkar, A., Schambach, J., Scharenberg, R. P., Schmah, A. M., Schmitz, N., Schuster, T. R., Seele, J., Seger, J., Seyboth, P., Shah, N., Shahaliev, E., Shao, M., Sharma, B., Sharma, M., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Singaraju, R. N., Skoby, M. J., Smirnov, N., Solanki, D., Sorensen, P., deSouza, U. G., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Steadman, S. G., Stevens, J. R., Stock, R., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Suarez, M. C., Sumbera, M., Sun, X. M., Sun, Y., Sun, Z., Surrow, B., Svirida, D. N., Symons, T. J. M., de Toledo, A. Szanto, Takahashi, J., Tang, A. H., Tang, Z., Tarini, L. H., Tarnowsky, T., Thein, D., Thomas, J. H., Tian, J., Timmins, A. R., Tlusty, D., Tokarev, M., Trainor, T. A., Trentalange, S., Tribble, R. E., Tribedy, P., Trzeciak, B. A., Tsai, O. D., Ullrich, T., Underwood, D. G., Van Buren, G., van Nieuwenhuizen, G., Vanfossen Jr., J. A., Varma, R., Vasconcelos, G. M. S., Videbæk, F., Viyogi, Y. P., Vokal, S., Voloshin, S. A., Vossen, A., Wada, M., Wang, F., Wang, G., Wang, H., Wang, J. S., Wang, Q., Wang, X. L., Wang, Y., Webb, G., Webb, J. C., Westfall, G. D., Whitten Jr., C., Wieman, H., Wissink, S. W., Witt, R., Witzke, W., Wu, Y. F., Xiao, Z., Xie, W., Xin, K., Xu, H., Xu, N., Xu, Q. H., Xu, W., Xu, Y., Xu, Z., Xue, L., Yang, Y., Yepes, P., Yi, Y., Yip, K., Yoo, I-K., Zawisza, M., Zbroszczyk, H., Zhang, J. B., Zhang, S., Zhang, W. M., Zhang, X. P., Zhang, Y., Zhang, Z. P., Zhao, F., Zhao, J., Zhong, C., Zhu, X., Zhu, Y. H., and Zoulkarneeva, Y.

Subjects
High Energy Physics - Experiment, Nuclear Experiment
Abstract

We report measurements of the charge-separated $W^{+(-)} \to e^{+(-)} + \nu_e(\bar{\nu}_e)$ and $Z/\gamma^* \to e^+e^-$ production cross sections at mid-rapidity in proton-proton collisions at $\sqrt{s}$ = 500 GeV. These results are based on 13.2 pb$^{-1}$ of data recorded in 2009 by the STAR detector at RHIC. Production cross sections for W bosons that decay via the $e \nu$ channel were measured to be $\sigma(pp \to W^+ X) \cdot BR(W^+ \to e^+ \nu_e)$ = 117.3 \pm 5.9(stat) \pm 6.2(syst) \pm 15.2(lumi) pb, and $\sigma(pp \to W^- X) \cdot BR(W^- \to e^- \bar{\nu}_e)$ = 43.3 \pm 4.6(stat) \pm 3.4(syst) \pm 5.6(lumi) pb. For $Z/\gamma^*$ production, $\sigma(pp \to Z/\gamma^* X) \cdot BR(Z/\gamma^* \to e^+ e^-)$ = 7.7 \pm 2.1(stat) $^{+0.5}_{-0.9}$(syst) \pm 1.0(lumi) pb for di-lepton invariant masses $m_{e^+e^-}$ between 70 and 110 GeV/$c^2$. First measurements of the W cross section ratio, $\sigma(pp \to W^+ X) / \sigma(pp \to W^- X)$, at $\sqrt{s}$ = 500 GeV are also reported. Theoretical predictions, calculated using recent parton distribution functions, are found to agree with the measured cross sections., Comment: 14 pages, 12 figures, submitted to Physical Review D

Published
2011
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47. Energy and system-size dependence of two- and four-particle $v_2$ measurements in heavy-ion collisions at RHIC and their implications on flow fluctuations and nonflow

Author

The STAR Collaboration, Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alakhverdyants, A. V., Alekseev, I., Alford, J., Anderson, B. D., Anson, C. D., Arkhipkin, D., Averichev, G. S., Balewski, J., Barnovska, Z., Beavis, D. R., Bellwied, R., Betancourt, M. J., Betts, R. R., Bhasin, A., Bhati, A. K., Bichsel, H., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Borowski, W., Bouchet, J., Brandin, A. V., Brovko, S. G., Bruna, E., Bueltmann, S., Bunzarov, I., Burton, T. P., Cai, X. Z., Caines, H., Calderon, M., Cebra, D., Cendejas, R., Cervantes, M. C., Chaloupka, P., Chattopadhyay, S., Chen, H. F., Chen, J. H., Chen, J. Y., Chen, L., Cheng, J., Cherney, M., Chikanian, A., Christie, W., Chung, P., Codrington, M. J. M., Corliss, R., Cramer, J. G., Crawford, H. J., Cui, X., Leyva, A. Davila, De Silva, L. C., Debbe, R. R., Dedovich, T. G., Deng, J., de Souza, R. Derradi, Dhamija, S., Didenko, L., Ding, F., Djawotho, P., Dong, X., Drachenberg, J. L., Draper, J. E., Du, C. M., Dunkelberger, L. E., Dunlop, J. C., Efimov, L. G., Elnimr, M., Engelage, J., Eppley, G., Eun, L., Evdokimov, O., Fatemi, R., Fedorisin, J., Fersch, R. G., Filip, P., Finch, E., Fisyak, Y., Gagliardi, C. A., Gangadharan, D. R., Geurts, F., Ghosh, P., Gliske, S., Gorbunov, Y. N., Grebenyuk, O. G., Grosnick, D., Gupta, S., Guryn, W., Haag, B., Hajkova, O., Hamed, A., Han, L-X., Harris, J. W., Hays-Wehle, J. P., Heppelmann, S., Hirsch, A., Hoffmann, G. W., Hofman, D. J., Horvat, S., Huang, B., Huang, H. Z., Huck, P., Humanic, T. J., Huo, L., Igo, G., Jacobs, W. W., Jena, C., Joseph, J., Judd, E. G., Kabana, S., Kang, K., Kapitan, J., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kesich, A., Kettler, D., Kikola, D. P., Kiryluk, J., Kisiel, A., Kizka, V., Klein, S. R., Koetke, D. D., Kollegger, T., Konzer, J., Koralt, I., Koroleva, L., Korsch, W., Kotchenda, L., Kravtsov, P., Krueger, K., Kumar, L., Lamont, M. A. C., Landgraf, J. M., LaPointe, S., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Leight, W., LeVine, M. J., Li, C., Li, L., Li, W., Li, X., Li, Y., Li, Z. M., Lima, L. M., Lisa, M. A., Liu, F., Ljubicic, T., Llope, W. J., Longacre, R. S., Lu, Y., Luo, X., Ma, G. L., Ma, Y. G., Mahapatra, D. P., Majka, R., Mall, O. I., Margetis, S., Markert, C., Masui, H., Matis, H. S., McDonald, D., McShane, T. S., Mioduszewski, S., Mitrovski, M. K., Mohammed, Y., Mohanty, B., Mondal, M. M., Morozov, B., Munhoz, M. G., Mustafa, M. K., Naglis, M., Nandi, B. K., Nasim, Md., Nayak, T. K., Nogach, L. V., Odyniec, G., Ogawa, A., Oh, K., Ohlson, A., Okorokov, V., Oldag, E. W., Oliveira, R. A. N., Olson, D., Pachr, M., Page, B. S., Pal, S. K., Pan, Pandit, Y., Panebratsev, Y., Pawlak, T., Pei, H., Perkins, C., Peryt, W., Pile, P., Planinic, M., Pluta, J., Plyku, D., Poljak, N., Porter, J., Poskanzer, A. M., Powell, C. B., Prindle, D., Pruneau, C., Pruthi, N. K., Pujahari, P. R., Putschke, J., Qiu, H., Raniwala, R., Raniwala, S., Redwine, R., Reed, R., Riley, C. K., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ruan, L., Rusnak, J., Sahoo, N. R., Sakrejda, I., Salur, S., Sandweiss, J., Sangaline, E., Sarkar, A., Schambach, J., Scharenberg, R. P., Schmah, A. M., Schmitz, N., Schuster, T. R., Seele, J., Seger, J., Seyboth, P., Shah, N., Shahaliev, E., Shao, M., Sharma, B., Sharma, M., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Singaraju, R. N., Skoby, M. J., Smirnov, N., Solanki, D., Sorensen, P., de Souza, U. G., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Steadman, S. G., Stevens, J. R., Stock, R., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Suarez, M. C., Sumbera, M., Sun, X. M., Sun, Y., Sun, Z., Surrow, B., Svirida, D. N., Symons, T. J. M., de Toledo, A. Szanto, Takahashi, J., Tang, A. H., Tang, Z., Tarini, L. H., Tarnowsky, T., Thein, D., Thomas, J. H., Tian, J., Timmins, A. R., Tlusty, D., Tokarev, M., Trentalange, S., Tribble, R. E., Tribedy, P., Trzeciak, B. A., Tsai, O. D., Ullrich, T., Underwood, D. G., Van Buren, G., van Nieuwenhuizen, G., Vanfossen, Jr., J. A., Varma, R., Vasconcelos, G. M. S., Videbaek, F., Viyogi, Y. P., Vokal, S., Voloshin, S. A., Vossen, A., Wada, M., Wang, F., Wang, G., Wang, H., Wang, J. S., Wang, Q., Wang, X. L., Wang, Y., Webb, G., Webb, J. C., Westfall, G. D., Whitten Jr., C., Wieman, H., Wissink, S. W., Witt, R., Witzke, W., Wu, Y. F., Xiao, Z., Xie, W., Xu, H., Xu, N., Xu, Q. H., Xu, W., Xu, Y., Xu, Z., Xue, L., Yang, Y., Yepes, P., Yi, Y., Yip, K., Yoo, I-K., Zawisza, M., Zbroszczyk, H., Zhan, W., Zhang, J. B., Zhang, S., Zhang, W. M., Zhang, X. P., Zhang, Y., Zhang, Z. P., Zhao, F., Zhao, J., Zhong, C., Zhu, X., Zhu, Y. H., and Zoulkarneeva, Y.

Subjects
Nuclear Experiment, High Energy Physics - Experiment
Abstract

We present STAR measurements of azimuthal anisotropy by means of the two- and four-particle cumulants $v_2$ ($v_2\{2\}$ and $v_2\{4\}$) for Au+Au and Cu+Cu collisions at center of mass energies $\sqrt{s_{_{\mathrm{NN}}}} = 62.4$ and 200 GeV. The difference between $v_2\{2\}^2$ and $v_2\{4\}^2$ is related to $v_{2}$ fluctuations ($\sigma_{v_2}$) and nonflow $(\delta_{2})$. We present an upper limit to $\sigma_{v_2}/v_{2}$. Following the assumption that eccentricity fluctuations $\sigma_{\epsilon}$ dominate $v_2$ fluctuations $\frac{\sigma_{v_2}}{v_2} \approx \frac{\sigma_{\epsilon}}{\epsilon}$ we deduce the nonflow implied for several models of eccentricity fluctuations that would be required for consistency with $v_2\{2\}$ and $v_2\{4\}$. We also present results on the ratio of $v_2$ to eccentricity., Comment: 15 pages, 12 Figures

Published
2011
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48. System size and energy dependence of near-side di-hadron correlations

Author

STAR Collaboration, Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alakhverdyants, A. V., Alekseev, I., Alford, J., Anderson, B. D., Anson, C. D., Arkhipkin, D., Averichev, G. S., Balewski, J., Barnby, L. S., Beavis, D. R., Bellwied, R., Betancourt, M. J., Betts, R. R., Bhasin, A., Bhati, A. K., Bichsel, H., Bielcik, J., Bielcikova, J., Bland, L. C., Bombara, M., Bordyuzhin, I. G., Borowski, W., Bouchet, J., Braidot, E., Brandin, A. V., Brovko, S. G., Bruna, E., Bueltmann, S., Bunzarov, I., Burton, T. P., Cai, X. Z., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Cendejas, R., Cervantes, M. C., Chaloupka, P., Chattopadhyay, S., Chen, H. F., Chen, J. H., Chen, J. Y., Chen, L., Cheng, J., Cherney, M., Chikanian, A., Christie, W., Chung, P., Codrington, M. J. M., Corliss, R., Cramer, J. G., Crawford, H. J., Cui, X., Leyva, A. Davila, De Silva, L. C., Debbe, R. R., Dedovich, T. G., Deng, J., Derevschikov, A. A., de Souza, R. Derradi, Dhamija, S., Didenko, L., Djawotho, P., Dong, X., Drachenberg, J. L., Draper, J. E., Du, C. M., Dunkelberger, L. E., Dunlop, J. C., Efimov, L. G., Elnimr, M., Engelage, J., Eppley, G., Eun, L., Evdokimov, O., Fatemi, R., Fedorisin, J., Fersch, R. G., Filip, P., Finch, E., Fisyak, Y., Gagliardi, C. A., Gaillard, L., Gangadharan, D. R., Geurts, F., Ghosh, P., Gliske, S., Gorbunov, Y. N., Grebenyuk, O. G., Grosnick, D., Gupta, A., Gupta, S., Guryn, W., Haag, B., Hajkova, O., Hamed, A., Han, L-X., Harris, J. W., Hays-Wehle, J. P., Heppelmann, S., Hirsch, A., Hoffmann, G. W., Hofman, D. J., Horvat, S., Huang, B., Huang, H. Z., Humanic, T. J., Huo, L., Igo, G., Jacobs, W. W., Jena, C., Jones, P. G., Joseph, J., Judd, E. G., Kabana, S., Kang, K., Kapitan, J., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kettler, D., Kikola, D. P., Kiryluk, J., Kisiel, A., Kizka, V., Klein, S. R., Koetke, D. D., Kollegger, T., Konzer, J., Koralt, I., Koroleva, L., Korsch, W., Kotchenda, L., Kravtsov, P., Krueger, K., Kumar, L., Lamont, M. A. C., Landgraf, J. M., LaPointe, S., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Leight, W., LeVine, M. J., Li, C., Li, L., Li, W., Li, X., Li, Y., Li, Z. M., Lima, L. M., Lisa, M. A., Liu, F., Ljubicic, T., Llope, W. J., Longacre, R. S., Lu, Y., Lukashov, E. V., Luo, X., Ma, G. L., Ma, Y. G., Mahapatra, D. P., Majka, R., Mall, O. I., Margetis, S., Markert, C., Masui, H., Matis, H. S., McDonald, D., McShane, T. S., Minaev, N. G., Mioduszewski, S., Mitrovski, M. K., Mohammed, Y., Mohanty, B., Mondal, M. M., Morozov, B., Morozov, D. A., Munhoz, M. G., Mustafa, M. K., Naglis, M., Nandi, B. K., Nattrass, C., Nasim, Md., Nayak, T. K., Nogach, L. V., Nurushev, S. B., Odyniec, G., Ogawa, A., Oh, K., Ohlson, A., Okorokov, V., Oldag, E. W., Oliveira, R. A. N., Olson, D., Pachr, M., Page, B. S., Pal, S. K., Pan, Pandit, Y., Panebratsev, Y., Pawlak, T., Pei, H., Perkins, C., Peryt, W., Pile, P., Planinic, M., Pluta, J., Plyku, D., Poljak, N., Porter, J., Poskanzer, A. M., Powell, C. B., Prindle, D., Pruneau, C., Pruthi, N. K., Pujahari, P. R., Putschke, J., Qiu, H., Raniwala, R., Raniwala, S., Ray, R. L., Redwine, R., Reed, R., Riley, C. K., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ruan, L., Rusnak, J., Sahoo, N. R., Sakrejda, I., Salur, S., Sandweiss, J., Sangaline, E., Sarkar, A., Schambach, J., Scharenberg, R. P., Schmah, A. M., Schmitz, N., Schuster, T. R., Seele, J., Seger, J., Seyboth, P., Shah, N., Shahaliev, E., Shao, M., Sharma, B., Sharma, M., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Singaraju, R. N., Skoby, M. J., Smirnov, N., Solanki, D., Sorensen, P., deSouza, U. G., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Steadman, S. G., Stevens, J. R., Stock, R., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Suarez, M. C., Sumbera, M., Sun, X. M., Sun, Y., Sun, Z., Surrow, B., Svirida, D. N., Symons, T. J. M., de Toledo, A. Szanto, Takahashi, J., Tang, A. H., Tang, Z., Tarini, L. H., Tarnowsky, T., Thein, D., Thomas, J. H., Tian, J., Timmins, A. R., Tlusty, D., Tokarev, M., Trentalange, S., Tribble, R. E., Tribedy, P., Trzeciak, B. A., Tsai, O. D., Ullrich, T., Underwood, D. G., Van Buren, G., van Nieuwenhuizen, G., Vanfossen, Jr., J. A., Varma, R., Vasconcelos, G. M. S., Vasiliev, A. N., Videbæ, F., Viyogi, Y. P., Vokal, S., Voloshin, S. A., Vossen, A., Wada, M., Wang, G., Wang, H., Wang, J. S., Wang, Q., Wang, X. L., Wang, Y., Webb, G., Webb, J. C., Westfall, G. D., Whitten Jr., C., Wieman, H., Wissink, S. W., Witt, R., Witzke, W., Wu, Y. F., Xiao, Z., Xie, W., Xu, H., Xu, N., Xu, Q. H., Xu, W., Xu, Y., Xu, Z., Xue, L., Yang, Y., Yepes, P., Yi, Y., Yip, K., Yoo, I-K., Zawisza, M., Zbroszczyk, H., Zhan, W., Zhang, J. B., Zhang, S., Zhang, W. M., Zhang, X. P., Zhang, Y., Zhang, Z. P., Zhao, F., Zhao, J., Zhong, C., Zhu, X., Zhu, Y. H., and Zoulkarneeva, Y.

Subjects
Nuclear Experiment
Abstract

Two-particle azimuthal ($\Delta\phi$) and pseudorapidity ($\Delta\eta$) correlations using a trigger particle with large transverse momentum ($p_T$) in $d$+Au, Cu+Cu and Au+Au collisions at $\sqrt{s_{{NN}}}$ =\xspace 62.4 GeV and 200~GeV from the STAR experiment at RHIC are presented. The \ns correlation is separated into a jet-like component, narrow in both $\Delta\phi$ and $\Delta\eta$, and the ridge, narrow in $\Delta\phi$ but broad in $\Delta\eta$. Both components are studied as a function of collision centrality, and the jet-like correlation is studied as a function of the trigger and associated $p_T$. The behavior of the jet-like component is remarkably consistent for different collision systems, suggesting it is produced by fragmentation. The width of the jet-like correlation is found to increase with the system size. The ridge, previously observed in Au+Au collisions at $\sqrt{s_{{NN}}}$ = 200 GeV, is also found in Cu+Cu collisions and in collisions at $\sqrt{s_{{NN}}}$ =\xspace 62.4 GeV, but is found to be substantially smaller at $\sqrt{s_{{NN}}}$ =\xspace 62.4 GeV than at $\sqrt{s_{{NN}}}$ = 200 GeV for the same average number of participants ($ \langle N_{\mathrm{part}}\rangle$). Measurements of the ridge are compared to models., Comment: 17 pages, 14 figures, submitted to Phys. Rev. C

Published
2011
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49. Directed and elliptic flow of charged particles in Cu+Cu collisions at $\sqrt{\bm {s_{NN}}} =$ 22.4 GeV

Author

Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alakhverdyants, A. V., Alekseev, I., Alford, J., Anderson, B. D., Anson, C. D., Arkhipkin, D., Averichev, G. S., Balewski, J., Beavis, D. R., Behera, N. K., Bellwied, R., Betancourt, M. J., Betts, R. R., Bhasin, A., Bhati, A. K., Bichsel, H., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Borowski, W., Bouchet, J., Braidot, E., Brandin, A. V., Bridgeman, A., Brovko, S. G., Bruna, E., Bueltmann, S., Bunzarov, I., Burton, T. P., Cai, X. Z., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Cendejas, R., Cervantes, M. C., Chaloupka, P., Chattopadhyay, S., Chen, H. F., Chen, J. H., Chen, J. Y., Chen, L., Cheng, J., Cherney, M., Chikanian, A., Choi, K. E., Christie, W., Chung, P., Codrington, M. J. M., Corliss, R., Cramer, J. G., Crawford, H. J., Cui, Leyva, A. Davila, De Silva, L. C., Debbe, R. R., Dedovich, T. G., Deng, J., Derevschikov, A. A., de Souza, R. Derradi, Didenko, L., Djawotho, P., Dogra, S. M., Dong, X., Drachenberg, J. L., Draper, J. E., Du, C. M., Dunlop, J. C., Efimov, L. G., Elnimr, M., Engelage, J., Eppley, G., Estienne, M., Eun, L., Evdokimov, O., Fatemi, R., Fedorisin, J., Fersch, R. G., Filip, P., Finch, E., Fine, V., Fisyak, Y., Gagliardi, C. A., Gangadharan, D. R., Geurts, F., Ghosh, P., Gorbunov, Y. N., Gordon, A., Grebenyuk, O. G., Grosnick, D., Gupta, A., Gupta, S., Guryn, W., Haag, B., Hajkova, O., Hamed, A., Han, L-X., Harris, J. W., Hays-Wehle, J. P., Heinz, M., Heppelmann, S., Hirsch, A., Hjort, E., Hoffmann, G. W., Hofman, D. J., Huang, B., Huang, H. Z., Humanic, T. J., Huo, L., Igo, G., Jacobs, P., Jacobs, W. W., Jena, C., Jin, F., Joseph, J., Judd, E. G., Kabana, S., Kang, K., Kapitan, J., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kettler, D., Kikola, D. P., Kiryluk, J., Kisiel, A., Kizka, V., Klein, S. R., Knospe, A. G., Koetke, D. D., Kollegger, T., Konzer, J., Koralt, I., Koroleva, L., Korsch, W., Kotchenda, L., Kouchpil, V., Kravtsov, P., Krueger, K., Krus, M., Kumar, L., Lamont, M. A. C., Landgraf, J. M., LaPointe, S., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Leight, W., LeVine, M. J., Li, C., Li, L., Li, N., Li, W., Li, X., Li, Y., Li, Z. M., Lima, 1 L. M., Lisa, M. A., Liu, F., Liu, H., Liu, J., Ljubicic, T., Llope, W. J., Longacre, R. S., Lu, Y., Lukashov, E. V., Luo, X., Ma, G. L., Ma, Y. G., Mahapatra, D. P., Majka, R., Mall, O. I., Manweiler, R., Margetis, S., Markert, C., Masui, H., Matis, H. S., McDonald, D., McShane, T. S., Meschanin, A., Milner, R., Minaev, N. G., Mioduszewski, S., Mitrovski, M. K., Mohammed, Y., Mohanty, B., Mondal, M. M., Morozov, B., Morozov, D. A., Munhoz, M. G., Mustafa, M. K., Naglis, M., Nandi, B. K., Nayak, T. K., Nogach, L. V., Nurushev, S. B., Odyniec, G., Ogawa, A., Oh, K., Ohlson, A., Okorokov, V., Oldag, E. W., Oliveira, R. A. N., Olson, D., Pachr, M., Page, B. S., Pal, S. K., Pandit, Y., Panebratsev, Y., Pawlak, T., Pei, H., Peitzmann, T., Perkins, C., Peryt, W., Pile, P., Planinic, M., Ploskon, M. A., Pluta, J., Plyku, D., Poljak, N., Porter, J., Poskanzer, A. M., Potukuchi, B. V. K. S., Powell, C. B., Prindle, D., Pruneau, C., Pruthi, N. K., Pujahari, P. R., Putschke, J., Qiu, H., Raniwala, R., Raniwala, S., Ray, R. L., Redwine, R., Reed, R., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ruan, L., Rusnak, J., Sahoo, N. R., Sakrejda, I., Salur, S., Sandweiss, J., Sangaline, E., Sarkar, A., Schambach, J., Scharenberg, R. P., Schaub, J., Schmah, A. M., Schmitz, N., Schuster, T. R., Seele, J., Seger, J., Selyuzhenkov, I., Seyboth, P., Shah, N., Shahaliev, E., Shao, M., Sharma, M., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Simon, F., Singaraju, R. N., Skoby, M. J., Smirnov, N., Solanki, D., Sorensen, P., deSouza, U. G., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Steadman, S. G., Stevens, J. R., Stock, R., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Suarez, M. C., Subba, N. L., Sumbera, M., Sun, X. M., Sun, Y., Sun, Z., Surrow, B., Svirida, D. N., Symons, T. J. M., de Toledo, A. Szanto, Takahashi, J., Tang, A. H., Tang, Z., Tarini, L. H., Tarnowsky, T., Thein, D., Thomas, J. H., Tian, J., Timmins, A. R., Tlusty, D., Tokarev, M., Trentalange, S., Tribble, R. E., Tribedy, P., Trzeciak, B. A., Tsai, O. D., Ullrich, T., Underwood, D. G., Van Buren, G., van Nieuwenhuizen, G., Vanfossen, Jr., J. A., Varma, R., Vasconcelos, G. M. S., Vasiliev, A. N., Videbæk, F., Viyogi, Y. P., Vokal, S., Voloshin, S. A., Wada, M., Walker, M., Wang, F., Wang, G., Wang, H., Wang, J. S., Wang, Q., Wang, X. L., Wang, Y., Webb, G., Webb, J. C., Westfall, G. D., Whitten Jr., C., Wieman, H., Wissink, S. W., Witt, R., Witzke, W., Wu, Y. F., Xiao, Z., Xie, W., Xu, H., Xu, N., Xu, Q. H., Xu, W., Xu, Y., Xu, Z., Xue, L., Yang, Y., Yepes, P., Yip, K., Yoo, I-K., Zawisza, M., Zbroszczyk, H., Zhan, W., Zhang, J. B., Zhang, S., Zhang, W. M., Zhang, X. P., Zhang, Y., Zhang, Z. P., Zhao, F., Zhao, J., Zhong, C., Zhu, X., Zhu, Y. H., and Zoulkarneeva, Y.

Subjects
Nuclear Experiment
Abstract

This paper reports results for directed flow $v_{1}$ and elliptic flow $v_{2}$ of charged particles in Cu+Cu collisions at $\sqrt{s_{NN}}=$ 22.4 GeV at the Relativistic Heavy Ion Collider. The measurements are for the 0-60% most central collisions, using charged particles observed in the STAR detector. Our measurements extend to 22.4 GeV Cu+Cu collisions the prior observation that $v_1$ is independent of the system size at 62.4 and 200 GeV, and also extend the scaling of $v_1$ with $\eta/y_{\rm beam}$ to this system. The measured $v_2(p_T)$ in Cu+Cu collisions is similar for $\sqrt{s_{NN}} = 22.4-200$ GeV. We also report a comparison with results from transport model (UrQMD and AMPT) calculations. The model results do not agree quantitatively with the measured $v_1(\eta), v_2(p_T)$ and $v_2(\eta)$., Comment: 10 pages,9 figures: Introduction part of the paper is expanded, Fig 9 is changed slightly, more discussion on summary

Published
2011
Full Text
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50. Anomalous centrality evolution of two-particle angular correlations from Au-Au collisions at $\sqrt{s_{\rm NN}}$ = 62 and 200 GeV

Author

STAR Collaboration, Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alakhverdyants, A. V., Alekseev, I., Alford, J., Anderson, B. D., Anson, C. D., Arkhipkin, D., Averichev, G. S., Balewski, J., Beavis, D. R., Bellwied, R., Betancourt, M. J., Betts, R. R., Bhasin, A., Bhati, A. K., Bichsel, H., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Borowski, W., Bouchet, J., Braidot, E., Brandin, A. V., Brovko, S. G., Bruna, E., Bueltmann, S., Bunzarov, I., Burton, T. P., Cai, X. Z., Caines, H., Calderon, M., Cebra, D., Cendejas, R., Cervantes, M. C., Chaloupka, P., Chattopadhyay, S., Chen, H. F., Chen, J. H., Chen, J. Y., Chen, L., Cheng, J., Cherney, M., Chikanian, A., Christie, W., Chung, P., Codrington, M. J. M., Corliss, R., Cramer, J. G., Crawford, H. J., Cui, X., Leyva, A. Davila, De Silva, L. C., Debbe, R. R., Dedovich, T. G., Deng, J., Derevschikov, A. A., de Souza, R. Derradi, Didenko, L., Djawotho, P., Dong, X., Drachenberg, J. L., Draper, J. E., Du, C. M., Dunlop, J. C., Efimov, L. G., Elnimr, M., Engelage, J., Eppley, G., Estienne, M., Eun, L., Evdokimov, O., Fatemi, R., Fedorisin, J., Fersch, R. G., Filip, P., Finch, E., Fine, V., Fisyak, Y., Gagliardi, C. A., Gangadharan, D. R., Geurts, F., Ghosh, P., Gorbunov, Y. N., Gordon, A., Grebenyuk, O. G., Grosnick, D., Gupta, A., Gupta, S., Guryn, W., Haag, B., Hajkova, O., Hamed, A., Han, L-X., Harris, J. W., Hays-Wehle, J. P., Heppelmann, S., Hirsch, A., Hoffmann, G. W., Hofman, D. J., Huang, B., Huang, H. Z., Humanic, T. J., Huo, L., Igo, G., Jacobs, W. W., Jena, C., Joseph, J., Judd, E. G., Kabana, S., Kang, K., Kapitan, J., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kettler, D., Kikola, D. P., Kiryluk, J., Kisiel, A., Kizka, V., Klein, S. R., Koetke, D. D., Kollegger, T., Konzer, J., Koralt, I., Koroleva, L., Korsch, W., Kotchenda, L., Kravtsov, P., Krueger, K., Kumar, L., Lamont, M. A. C., Landgraf, J. M., LaPointe, S., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Leight, W., LeVine, M. J., Li, C., Li, L., Li, W., Li, X., Li, Y., Li, Z. M., Lima, L. M., Lisa, M. A., Liu, F., Ljubicic, T., Llope, W. J., Longacre, R. S., Lu, Y., Lukashov, E. V., Luo, X., Ma, G. L., Ma, Y. G., Mahapatra, D. P., Majka, R., Mall, O. I., Manweiler, R., Margetis, S., Markert, C., Masui, H., Matis, H. S., McDonald, D., McShane, T. S., Meschanin, A., Milner, R., Minaev, N. G., Mioduszewski, S., Mitrovski, M. K., Mohammed, Y., Mohanty, B., Mondal, M. M., Morozov, B., Morozov, D. A., Munhoz, M. G., Mustafa, M. K., Naglis, M., Nandi, B. K., Nasim, Md., Nayak, T. K., Nogach, L. V., Nurushev, S. B., Odyniec, G., Ogawa, A., Oh, K., Ohlson, A., Okorokov, V., Oldag, E. W., Oliveira, R. A. N., Olson, D., Pachr, M., Page, B. S., Pal, S. K., Pandit, Y., Panebratsev, Y., Pawlak, T., Pei, H., Peitzmann, T., Perkins, C., Peryt, W., Pile, P., Planinic, M., Pluta, J., Plyku, D., Poljak, N., Porter, J., Powell, C. B., Prindle, D., Pruneau, C., Pruthi, N. K., Pujahari, P. R., Putschke, J., Qiu, H., Raniwala, R., Raniwala, S., Ray, R. L., Redwine, R., Reed, R., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ruan, L., Rusnak, J., Sahoo, N. R., Sakrejda, I., Salur, S., Sandweiss, J., Sangaline, E., Sarkar, A., Schambach, J., Scharenberg, R. P., Schaub, J., Schmah, A. M., Schmitz, N., Schuster, T. R., Seele, J., Seger, J., Selyuzhenkov, I., Seyboth, P., Shah, N., Shahaliev, E., Shao, M., Sharma, M., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Simon, F., Singaraju, R. N., Skoby, M. J., Smirnov, N., Solanki, D., Sorensen, P., de Souza, U. G., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Steadman, S. G., Stevens, J. R., Stock, R., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Suarez, M. C., Sumbera, M., Sun, X. M., Sun, Y., Sun, Z., Surrow, B., Svirida, D. N., Symons, T. J. M., de Toledo, A. Szanto, Takahashi, J., Tang, A. H., Tang, Z., Tarini, L. H., Tarnowsky, T., Thein, D., Thomas, J. H., Tian, J., Timmins, A. R., Tlusty, D., Tokarev, M., Trainor, T. A., Trentalange, S., Tribble, R. E., Tribedy, P., Trzeciak, B. A., Tsai, O. D., Ullrich, T., Underwood, D. G., Van Buren, G., van Nieuwenhuizen, G., Vanfossen, Jr., J. A., Varma, R., Vasconcelos, G. M. S., Vasiliev, A. N., Videbaek, F., Viyogi, Y. P., Vokal, S., Wada, M., Walker, M., Wang, F., Wang, G., Wang, H., Wang, J. S., Wang, Q., Wang, X. L., Wang, Y., Webb, G., Webb, J. C., Westfall, G. D., Whitten Jr., C., Wieman, H., Wissink, S. W., Witt, R., Witzke, W., Wu, Y. F., Xiao, Z., Xie, W., Xu, H., Xu, N., Xu, Q. H., Xu, W., Xu, Y., Xu, Z., Xue, L., Yang, Y., Yepes, P., Yip, K., Yoo, I-K., Zawisza, M., Zbroszczyk, H., Zhan, W., Zhang, J. B., Zhang, S., Zhang, W. M., Zhang, X. P., Zhang, Y., Zhang, Z. P., Zhao, F., Zhao, J., Zhong, C., Zhu, X., Zhu, Y. H., and Zoulkarneeva, Y.

Subjects
Nuclear Experiment
Abstract

We present two-dimensional (2D) two-particle angular correlations on relative pseudorapidity $\eta$ and azimuth $\phi$ for charged particles from Au-Au collisions at $\sqrt{s_{\rm NN}} = 62$ and 200 GeV with transverse momentum $p_t \geq 0.15$ GeV/$c$, $|\eta| \leq 1$ and $2\pi$ azimuth. Observed correlations include a {same-side} (relative azimuth $< \pi/2$) 2D peak, a closely-related away-side azimuth dipole, and an azimuth quadrupole conventionally associated with elliptic flow. The same-side 2D peak and away-side dipole are explained by semihard parton scattering and fragmentation (minijets) in proton-proton and peripheral nucleus-nucleus collisions. Those structures follow N-N binary-collision scaling in Au-Au collisions until mid-centrality where a transition to a qualitatively different centrality trend occurs within a small centrality interval. Above the transition point the number of same-side and away-side correlated pairs increases rapidly {relative to} binary-collision scaling, the $\eta$ width of the same-side 2D peak also increases rapidly ($\eta$ elongation) and the $\phi$ width actually decreases significantly. Those centrality trends are more remarkable when contrasted with expectations of jet quenching in a dense medium. Observed centrality trends are compared to {\sc hijing} predictions and to the expected trends for semihard parton scattering and fragmentation in a thermalized opaque medium. We are unable to reconcile a semihard parton scattering and fragmentation origin for the observed correlation structure and centrality trends with heavy ion collision scenarios which invoke rapid parton thermalization. On the other hand, if the collision system is effectively opaque to few-GeV partons the observations reported here would be inconsistent with a minijet picture., Comment: 26 pages, 8 figures, 2 tables

Published
2011
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