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Your search keyword '"Steadman, S."' showing total 351 results
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351 results on '"Steadman, S."'

1. Measurement of Moller Scattering at 2.5 MeV

Author

Epstein, C. S., Johnston, R., Lee, S., Bernauer, J. C., Corliss, R., Dow, K., Fisher, P., Friscic, I., Hasell, D., Milner, R. G., Moran, P., Steadman, S. G., Wang, Y., Dodge, J., Ihloff, E., Kelsey, J., Vidal, C., and Cooke, C. M.

Subjects
Nuclear Experiment, Physics - Instrumentation and Detectors
Abstract

Moller scattering is one of the most fundamental processes in QED. Understanding it to high precision is necessary for a variety of modern nuclear and particle physics experiments. In a recent calculation, existing soft-photon radiative corrections were combined with new hard-photon bremsstrahlung calculations to take into account the effect of photon emission at any photon energy, where the electron mass was included at all steps. To test the calculation, an experiment was carried out using the 3 MV Van de Graaff electrostatic accelerator at the MIT High Voltage Research Laboratory. Momentum spectra at three scattering angles at an incident electron energy of 2.5 MeV are reported here, and compared to the simulated radiative Moller spectra, based on our previous calculation. Good agreement between the measurements and our calculation is observed in the momentum spectrum at the three angles.

Published
2019
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2. Design and Operation of a Windowless Gas Target Internal to a Solenoidal Magnet for Use with a Megawatt Electron Beam

Author

Lee, S., Corliss, R., Friščić, I., Alarcon, R., Aulenbacher, S., Balewski, J., Benson, S., Bernauer, J. C., Bessuille, J., Boyce, J., Coleman, J., Douglas, D., Epstein, C. S., Fisher, P., Frierson, S., Garçon, M., Grames, J., Hasell, D., Hernandez-Garcia, C., Ihloff, E., Johnston, R., Jordan, K., Kazimi, R., Kelsey, J., Kohl, M., Liyanage, A., McCaughan, M., Milner, R. G., Moran, P., Nazeer, J., Palumbo, D., Poelker, M., Randall, G., Steadman, S. G., Tennant, C., Tschalär, C., Vidal, C., Vogel, C., Wang, Y., and Zhang, S.

Subjects
Physics - Instrumentation and Detectors, Nuclear Experiment
Abstract

A windowless hydrogen gas target of nominal thickness $10^{19}$ cm$^{-2}$ is an essential component of the DarkLight experiment, which is designed to utilize the megawatt electron beam at an Energy Recovery Linac (ERL). The design of such a target is challenging because the pressure drops by many orders of magnitude between the central, high-density section of the target and the surrounding beamline, resulting in laminar, transitional, and finally molecular flow regimes. The target system was assembled and operated at Jefferson Lab's Low Energy Recirculator Facility (LERF) in 2016, and subsequently underwent several revisions and calibration tests at MIT Bates in 2017. The system at dynamic equilibrium was simulated in COMSOL to provide a better understanding of its optimal operation at other working points. We have determined that a windowless gas target with sufficiently high density for DarkLight's experimental needs is feasible in an ERL environment., Comment: 11 pages, 14 figures; v2: minor improvements; v3: author list updated; v4: minor revision

Published
2019
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3. Realization of a Large-Acceptance Faraday Cup for 3 MeV Electrons

Author

Johnston, R., Bernauer, J., Cooke, C. M., Corliss, R., Epstein, C. S., Fisher, P., Friščić, I., Hasell, D., Ihloff, E., Kelsey, J., Lee, S., Milner, R. G., Moran, P., Steadman, S. G., and Vidal, C.

Subjects
Physics - Instrumentation and Detectors, Nuclear Experiment, Physics - Accelerator Physics
Abstract

The design, construction, installation, and testing of a Faraday Cup intended to measure the current of a 3 MeV, 1 microampere electron beam is described. Built as a current monitor for a M{\o}ller scattering measurement at the MIT High Voltage Research Laboratory, the device combines a large angular acceptance with the capability to measure a continuous, low energy beam. Bench studies of its performance demonstrate current measurements accurate to the percent level at 1 microampere. The Faraday Cup was designed and constructed at MIT and has been in use at the HVRL since 2017, providing a significantly more detailed measurement of beam current than was previously available., Comment: 4 pages

Published
2018
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5. The DarkLight Experiment: A Precision Search for New Physics at Low Energies

Author

Balewski, J., Bernauer, J., Bessuille, J., Corliss, R., Cowan, R., Epstein, C., Fisher, P., Hasell, D., Ihloff, E., Kahn, Y., Kelsey, J., Milner, R., Steadman, S., Thaler, J., Tschalaer, C., Vidal, C., Benson, S., Boyce, J., Douglas, D., Evtushenko, P., Hernandez-Garcia, C., Keith, C., Tennant, C., Zhang, S., Alarcon, R., Blyth, D., Dipert, R., Ice, L., Randall, G., Dongwi, B., Kalantarians, N., Kohl, M., Liyanage, A., Nazeer, J., Garcon, M., Cervantes, R., Dehmelt, K., Deshpande, A., Feege, N., and Surrow, B.

Subjects
Physics - Instrumentation and Detectors, High Energy Physics - Experiment
Abstract

We describe the current status of the DarkLight experiment at Jefferson Laboratory. DarkLight is motivated by the possibility that a dark photon in the mass range 10 to 100 MeV/c$^2$ could couple the dark sector to the Standard Model. DarkLight will precisely measure electron proton scattering using the 100 MeV electron beam of intensity 5 mA at the Jefferson Laboratory energy recovering linac incident on a windowless gas target of molecular hydrogen. The complete final state including scattered electron, recoil proton, and e+e- pair will be detected. A phase-I experiment has been funded and is expected to take data in the next eighteen months. The complete phase-II experiment is under final design and could run within two years after phase-I is completed. The DarkLight experiment drives development of new technology for beam, target, and detector and provides a new means to carry out electron scattering experiments at low momentum transfers., Comment: Whitepaper submitted to Town Meeting on Fundamental and Symmetries and Neutrinos, O'Hare airport, Chicago, IL

Published
2014

6. 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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7. 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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8. 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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9. 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

10. 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
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11. 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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12. 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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13. 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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14. 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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15. 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
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16. 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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17. Strangeness Enhancement in Cu+Cu and Au+Au Collisions at \sqrt{s_{NN}} = 200 GeV

Author

STAR Collaboration, Agakishiev, H., 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., Behera, N. K., Bellwied, R., Betancourt, M. J., Betts, R. R., Bhasin, A., Bhati, A. K., Bichsel, H., Bielcik, J., Bielcikova, J., Biritz, B., Bland, L. C., 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., Chajecki, Z., 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., Dash, S., Leyva, A. Davila, De Silva, L. C., Debbe, R. R., Dedovich, T. G., Derevschikov, A. A., de Souza, R. Derradi, Didenko, L., Djawotho, P., Dogra, S. M., Dong, X., Drachenberg, J. L., Draper, J. E., 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., Geromitsos, A., Geurts, F., Ghosh, P., Gorbunov, Y. N., Gordon, A., Grebenyuk, O., Grosnick, D., Guertin, S. M., Gupta, A., 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., Jones, P. G., Jena, C., Jin, F., Joseph, J., Judd, E. G., Kabana, S., Kang, K., Kapitan, J., Kauder, K., Ke, H., Keane, D., Kechechyan, A., Kettler, D., Kikola, D. P., Kiryluk, J., Kisiel, A., Kizka, V., 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., Kurnadi, P., 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., Lisa, M. A., Liu, F., Liu, H., Liu, J., Ljubicic, T., Llope, W. J., Longacre, R. S., Love, W. A., Lu, Y., Lukashov, E. V., Luo, X., Ma, G. L., Ma, Y. G., Mahapatra, D. P., Majka, R., Mall, O. I., Mangotra, L. K., Manweiler, R., Margetis, S., Markert, C., Masui, H., Matis, H. S., Matulenko, Yu. A., McDonald, D., McShane, T. S., Meschanin, A., Milner, R., Minaev, N. G., Mioduszewski, S., Mischke, A., Mitrovski, M. K., Mohanty, B., Mondal, M. M., Morozov, B., Morozov, D. A., Munhoz, M. G., Naglis, M., Nandi, B. K., Nayak, T. K., Netrakanti, P. K., Nelson, J. M., Nogach, L. V., Nurushev, S. B., Odyniec, G., Ogawa, A., Oh, K., Ohlson, A., Okorokov, V., Oldag, E. W., Olson, D., Pachr, M., Page, B. S., Pal, S. K., Pandit, Y., Panebratsev, Y., Pawlak, T., Pei, H., Peitzmann, T., Perkins, C., Peryt, W., Phatak, S. C., Pile, P., Planinic, M., Ploskon, M. A., Pluta, J., Plyku, D., Poljak, N., 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., Rose, A., Ruan, L., Rusnak, J., Sahoo, N. R., Sakai, S., Sakrejda, I., Sakuma, T., Salur, S., Sandweiss, J., Sangaline, E., Sarkar, A., Schambach, J., Scharenberg, R. P., Schmah, A. M., Schuster, T. R., Seele, J., Seger, J., Selyuzhenkov, I., Seyboth, P., 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., 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., 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., Tram, V. N., Trentalange, S., Tribble, R. E., Tribedy, P., 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., 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, J., Zhong, C., Zhou, W., Zhu, X., Zhu, Y. H., Zoulkarneev, R., and Zoulkarneeva, Y.

Subjects
Nuclear Experiment
Abstract

We report new STAR measurements of mid-rapidity yields for the $\Lambda$, $\bar{\Lambda}$, $K^{0}_{S}$, $\Xi^{-}$, $\bar{\Xi}^{+}$, $\Omega^{-}$, $\bar{\Omega}^{+}$ particles in Cu+Cu collisions at \sNN{200}, and mid-rapidity yields for the $\Lambda$, $\bar{\Lambda}$, $K^{0}_{S}$ particles in Au+Au at \sNN{200}. We show that at a given number of participating nucleons, the production of strange hadrons is higher in Cu+Cu collisions than in Au+Au collisions at the same center-of-mass energy. We find that aspects of the enhancement factors for all particles can be described by a parameterization based on the fraction of participants that undergo multiple collisions.

Published
2011
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18. Studies of di-jet survival and surface emission bias in Au+Au collisions via angular correlations with respect to back-to-back leading hadrons

Author

Agakishiev, H., 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., Biritz, B., 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., Calderon, M., Cebra, D., Cendejas, R., Cervantes, M. C., Chajecki, Z., 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., Dash, S., Leyva, A. Davila, De Silva, L. C., Debbe, R. R., Dedovich, T. G., Derevschikov, A. A., de Souza, R. Derradi, Didenko, L., Djawotho, P., Dogra, S. M., Dong, X., Drachenberg, J. L., Draper, J. E., 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., Geromitsos, A., Geurts, F., Ghosh, P., Gorbunov, Y. N., Gordon, A., Grebenyuk, O. G., Grosnick, D., Guertin, S. M., Gupta, A., 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., Kurnadi, P., 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., Lisa, M. A., Liu, F., Liu, H., Liu, J., Ljubicic, T., Llope, W. J., Longacre, R. S., Love, W. A., Lu, Y., Lukashov, E. V., Luo, X., Ma, G. L., Ma, Y. G., Mahapatra, D. P., Majka, R., Mall, O. I., Mangotra, L. K., Manweiler, R., Margetis, S., Markert, C., Masui, H., Matis, H. S., Matulenko, Yu. A., McDonald, D., McShane, T. S., Meschanin, A., Milner, R., Minaev, N. G., Mioduszewski, S., Mischke, A., 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., Netrakanti, P. K., Nogach, L. V., Nurushev, S. B., Odyniec, G., Ogawa, A., Oh, K., Ohlson, A., Okorokov, V., Oldag, E. W., Olson, D., Pachr, M., Page, B. S., Pal, S. K., Pandit, Y., Panebratsev, Y., Pawlak, T., Pei, H., Peitzmann, T., Perkins, C., Peryt, W., Phatak, S. C., 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., Rose, A., Ruan, L., Rusnak, J., Sahoo, N. R., Sakai, S., 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., Selyuzhenkov, I., Seyboth, P., 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., Sorensen, P., 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., 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., Trainor, T. A., Tram, V. N., Trentalange, S., Tribble, R. E., Tribedy, P., 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., 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, J., Zhong, C., Zhou, W., Zhu, X., Zhu, Y. H., Zoulkarneev, R., and Zoulkarneeva, Y.

Subjects
Nuclear Experiment
Abstract

We report first results from an analysis based on a new multi-hadron correlation technique, exploring jet-medium interactions and di-jet surface emission bias at RHIC. Pairs of back-to-back high transverse momentum hadrons are used for triggers to study associated hadron distributions. In contrast with two- and three-particle correlations with a single trigger with similar kinematic selections, the associated hadron distribution of both trigger sides reveals no modification in either relative pseudo-rapidity or relative azimuthal angle from d+Au to central Au+Au collisions. We determine associated hadron yields and spectra as well as production rates for such correlated back-to-back triggers to gain additional insights on medium properties., Comment: By the STAR Collaboration. 6 pages, 2 figures

Published
2011
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19. Phobos results on charged particle multiplicity and pseudorapidity distributions in Au+Au, Cu+Cu, d+Au, and p+p collisions at ultra-relativistic energies

Author

Alver, B., Back, B. B., Baker, M. D., Ballintijn, M., Barton, D. S., Betts, R. R., Bickley, A. A., Bindel, R., Budzanowski, A., Busza, W., Carroll, A., Chai, Z., Chetluru, V., Decowski, M. P., Garcıa, E., Gburek, T., George, N., Gulbrandsen, K., Gushue, S., Halliwell, C., Hamblen, J., Heintzelman, G. A., Henderson, C., Hofman, D. J., Hollis, R. S., Holynski, R., Holzman, B., Iordanova, A., Johnson, E., Kane, J. L., Katzy, J., Khan, N., Kucewicz, J. Kotula W., Kulinich, P., Kuo, C. M., Li, W., Lin, W. T., Loizides, C., Manly, S., McLeod, D., Michalowski, J., Mignerey, A. C., Nouicer, R., Olszewski, A., Pak, R., Park, I. C., Pernegger, H., Reed, C., Remsberg, L. P., Reuter, M., Roland, C., Roland, G., Rosenberg, L., Sagerer, J., Sarin, P., Sawicki, P., Sedykh, I., Skulski, W., Smith, C. E., Steadman, S. G., Steinberg, P., Stephans, G. S. F., Stodulski, M., Sukhanov, A., Tonjes, M. B., Trzupek, A., Vale, C., van Nieuwenhuizen, G. J., Vaurynovich, S. S., Verdier, R., Veres, G. I., Wadsworth, B., Walters, P., Wenger, E., Wolfs, F. L. H., Wosiek, B., Wozniak, K., Wuosmaa, A. H., and Wyslouch, B.

Subjects
Nuclear Experiment
Abstract

Pseudorapidity distributions of charged particles emitted in $Au+Au$, $Cu+Cu$, $d+Au$, and $p+p$ collisions over a wide energy range have been measured using the PHOBOS detector at RHIC. The centrality dependence of both the charged particle distributions and the multiplicity at midrapidity were measured. Pseudorapidity distributions of charged particles emitted with $|\eta|<5.4$, which account for between 95% and 99% of the total charged-particle emission associated with collision participants, are presented for different collision centralities. Both the midrapidity density, $dN_{ch}/d\eta$, and the total charged-particle multiplicity, $N_{ch}$, are found to factorize into a product of independent functions of collision energy, $\sqrt{s_{_{NN}}}$, and centrality given in terms of the number of nucleons participating in the collision, $N_{part}$. The total charged particle multiplicity, observed in these experiments and those at lower energies, assumes a linear dependence of $(\ln s_{_{NN}})^2$ over the full range of collision energy of $\sqrt{s_{_{NN}}}$=2.7-200 GeV., Comment: 25 pages, 29 figures, 8 tables

Published
2010
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20. Measurements of Dihadron Correlations Relative to the Event Plane in Au+Au Collisions at $\sqrt{s_{_{\rm NN}}}=200$ GeV

Author

Agakishiev, H., 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., Biritz, B., Bland, L. C., 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., Sanchez, M. Calderon de la Barca, Cebra, D., Cendejas, R., Cervantes, M. C., Chajecki, Z., 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., Dash, S., Leyva, A. Davila, De Silva, L. C., Debbe, R. R., Dedovich, T. G., Derevschikov, A. A., de Souza, R. Derradi, Didenko, L., Djawotho, P., Dogra, S. M., Dong, X., Drachenberg, J. L., Draper, J. E., Dunlop, J. C., Efimov, L. G., Elnimr, M., Engelage, J., Eppley, G., Estienne, M., Eun, L., Evdokimov, O., Fatemi, R., Fedorisin, J., Feng, A., Fersch, R. G., Filip, P., Finch, E., Fine, V., Fisyak, Y., Gagliardi, C. A., Gangadharan, D. R., Geromitsos, A., Geurts, F., Ghosh, P., Gorbunov, Y. N., Gordon, A., Grebenyuk, O., Grosnick, D., Guertin, S. M., Gupta, A., 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., Hofmann, 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., Keane, D., Kechechyan, A., Kettler, D., Kikola, D. P., Kiryluk, J., Kisiel, A., Kizka, V., 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., Kurnadi, P., 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., Lisa, M. A., Liu, F., Liu, H., Liu, J., Ljubicic, T., Llope, W. J., Longacre, R. S., Love, W. A., Lu, Y., Lukashov, E. V., Luo, X., Ma, G. L., Ma, Y. G., Mahapatra, D. P., Majka, R., Mall, O. I., Mangotra, L. K., Manweiler, R., Margetis, S., Markert, C., Masui, H., Matis, H. S., Matulenko, Yu. A., McDonald, D., McShane, T. S., Meschanin, A., Milner, R., Minaev, N. G., Mioduszewski, S., Mischke, A., Mitrovski, M. K., Mohanty, B., Mondal, M. M., Morozov, B., Morozov, D. A., Munhoz, M. G., Naglis, M., Nandi, B. K., Nayak, T. K., Netrakanti, P. K., Nogach, L. V., Nurushev, S. B., Odyniec, G., Ogawa, A., Oh, Ohlson, Okorokov, V., Oldag, E. W., Olson, D., Pachr, M., Page, B. S., Pal, S. K., Pandit, Y., Panebratsev, Y., Pawlak, T., Pei, H., Peitzmann, T., Perkins, C., Peryt, W., Phatak, S. C., Pile, P., Planinic, M., Ploskon, M. A., Pluta, J., Plyku, D., Poljak, N., Poskanzer, A. M., Potukuchi, B. V. K. S., Powell, C. B., Prindle, D., 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., Rose, A., Ruan, L., Rusnak, J., Sahoo, N. R., Sakai, S., Sakrejda, I., Sakuma, T., 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., Selyuzhenkov, I., Seyboth, P., 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., 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., 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., Tram, V. N., Trentalange, S., Tribble, R. E., Tribedy, 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, 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, J., Zhong, C., Zhou, W., Zhu, X., Zhu, Y. H., Zoulkarneev, R., and Zoulkarneeva, Y.

Subjects
Nuclear Experiment, Nuclear Theory
Abstract

Dihadron azimuthal correlations containing a high transverse momentum ($p_T$) 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 $\sqrt{s_{_{\rm NN}}}=200$ GeV as a function of the trigger particle's azimuthal angle relative to the event plane, $\phi_s=|\phi_t-\psi_{\rm EP}|$. The azimuthal correlation is studied as a function of both the trigger and associated particle $p_T$. 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 $\phi_s$, with a double-peak structure for out-of-plane trigger particles. The near-side ridge (long range pseudo-rapidity $\Delta\eta$ correlation) appears to drop with increasing $\phi_s$ while the jet-like component remains approximately constant. The correlation functions are further studied with 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 $\phi_s$-dependence of the ridge or the away-side double-peak structure. ..., Comment: 54 pages, 40 figures, 6 tables. As published

Published
2010
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25. Measurements of dihadron correlations relative to the event plane in Au+Au collisions at $\sqrt{s_{NN}}=200$ GeV

Author

Agakishiev, H., 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., Biritz, B., Bland, L. C., 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., Sanchez, M. Calderon de la Barca, Cebra, D., Cendejas, R., Cervantes, M. C., Chajecki, Z., 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., Dash, S., Leyva, A. Davila, De Silva, L. C., Debbe, R. R., Dedovich, T. G., Derevschikov, A. A., de Souza, R. Derradi, Didenko, L., Djawotho, P., Dogra, S. M., Dong, X., Drachenberg, J. L., Draper, J. E., Dunlop, J. C., Efimov, L. G., Elnimr, M., Engelage, J., Eppley, G., Estienne, M., Eun, L., Evdokimov, O., Fatemi, R., Fedorisin, J., Feng, A., Fersch, R. G., Filip, P., Finch, E., Fine, V., Fisyak, Y., Gagliardi, C. A., Gangadharan, D. R., Geromitsos, A., Geurts, F., Ghosh, P., Gorbunov, Y. N., Gordon, A., Grebenyuk, O., Grosnick, D., Guertin, S. M., Gupta, A., 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., Hofmann, 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., Keane, D., Kechechyan, A., Kettler, D., Kikola, D. P., Kiryluk, J., Kisiel, A., Kizka, V., 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., Kurnadi, P., 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., Lisa, M. A., Liu, F., Liu, H., Liu, J., Ljubicic, T., Llope, W. J., Longacre, R. S., Love, W. A., Lu, Y., Lukashov, E. V., Luo, X., Ma, G. L., Ma, Y. G., Mahapatra, D. P., Majka, R., Mall, O. I., Mangotra, L. K., Manweiler, R., Margetis, S., Markert, C., Masui, H., Matis, H. S., Matulenko, Yu. A., McDonald, D., McShane, T. S., Meschanin, A., Milner, R., Minaev, N. G., Mioduszewski, S., Mischke, A., Mitrovski, M. K., Mohanty, B., Mondal, M. M., Morozov, B., Morozov, D. A., Munhoz, M. G., Naglis, M., Nandi, B. K., Nayak, T. K., Netrakanti, P. K., Nogach, L. V., Nurushev, S. B., Odyniec, G., Ogawa, A., Ohlson, Okorokov, V., Oldag, E. W., Olson, D., Pachr, M., Page, B. S., Pal, S. K., Pandit, Y., Panebratsev, Y., Pawlak, T., Pei, H., Peitzmann, T., Perkins, C., Peryt, W., Phatak, S. C., Pile, P., Planinic, M., Ploskon, M. A., Pluta, J., Plyku, D., Poljak, N., Poskanzer, A. M., Potukuchi, B. V. K. S., Powell, C. B., Prindle, D., 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., Rose, A., Ruan, L., Rusnak, J., Sahoo, N. R., Sakai, S., Sakrejda, I., Sakuma, T., 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., Selyuzhenkov, I., Seyboth, P., 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., 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., 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., Tram, V. N., Trentalange, S., Tribble, R. E., Tribedy, 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, 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, J., Zhong, C., Zhou, W., Zhu, X., Zhu, Y. H., Zoulkarneev, R., Zoulkarneeva, Y., Laboratoire de physique subatomique et des technologies associées (SUBATECH), Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-IMT Atlantique Bretagne-Pays de la Loire (IMT Atlantique), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT), and STAR

Subjects
heavy ion: scattering, Nuclear Theory, nucl-th, transverse momentum: high, [PHYS.NUCL]Physics [physics]/Nuclear Theory [nucl-th], FOS: Physical sciences, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], nucl-ex, transverse momentum: momentum spectrum, dihadron: angular correlation, Nuclear Theory (nucl-th), 25.75.Dw, path length: dependence, correlation function, Nuclear Experiment (nucl-ex), Nuclear Experiment, impact parameter: dependence, Brookhaven RHIC Coll, STAR, 25.75.-q, correlation: long-range, gold, flow: anisotropy, charged particle: trigger, nuclear matter, 200 GeV-cms/nucleon, jet: quenching
Abstract

Dihadron azimuthal correlations containing a high transverse momentum ($p_T$) 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 $\sqrt{s_{_{\rm NN}}}=200$ GeV as a function of the trigger particle's azimuthal angle relative to the event plane, $\phi_s=|\phi_t-\psi_{\rm EP}|$. The azimuthal correlation is studied as a function of both the trigger and associated particle $p_T$. 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 $\phi_s$, with a double-peak structure for out-of-plane trigger particles. The near-side ridge (long range pseudo-rapidity $\Delta\eta$ correlation) appears to drop with increasing $\phi_s$ while the jet-like component remains approximately constant. The correlation functions are further studied with 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 $\phi_s$-dependence of the ridge or the away-side double-peak structure. ..., Comment: 54 pages, 40 figures, 6 tables. As published

Published
2021

29. PHOBOS at RHIC: Some global observations

Author

Carroll, Alan S., Back, B. B., Baker, M. D., Barton, D. S., Betts, R. R., Ballintijn, M., Bickley, A. A., Bindel, R., Budzanowski, A., Busza, W., Carroll, A., Decowski, M. P., García, E., George, N., Gulbrandsen, K., Gushue, S., Halliwell, C., Hamblen, J., Heintzelman, G. A., Henderson, C, Hofman, D. J., Hollis, R. S., Hoyłyński, R., Holzman, B., Iordanova, A., Johnson, E., Kane, J. L., Katzy, J., Khan, N., Kucewicz, W., Kulinich, P., Kuo, C. M., Lin, W. T., Manly, S., McLeod, D., Michałowski, J., Mignerey, A. C., Nouicer, R., Olszewski, A., Pak, R., Park, I. C., Pernegger, H., Reed, C., Remsberg, L. P., Reuter, M., Roland, C., Roland, G., Rosenberg, L., Sagerer, J., Sarin, P., Sawicki, P., Skulski, W., Steadman, S. G., Steinberg, P., Stephans, G. S. F., Stodulski, M., Sukhanov, A., Tang, J.-L., Teng, R., Trzupek, A., Vale, C., van Nieuwenhuizen, G. J., Verdier, R., Wadsworth, B., Wolfs, F. L. H., Wosiek, B., Woźniak, K., Wuosmaa, A. H., Wysłouch, B., and For the PHOBOS Collaboration

Published
2003
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31. A first look at Au+Au collisions at RHIC energies using the PHOBOS detector

Author

Back, Birger, Baker, M. D., Barton, D. S., Betts, R. R., Bindel, R., Budzanowski, A., Busza, W., Carroll, A., Corbo, J., Decowski, M. P., Garcia, E., George, N., Gulbrandsen, K., Gushue, S., Halliwell, C., Hamblen, J., Heintzelman, G. A., Henderson, C., Hicks, D., Hofman, D. J., Hollis, R., Holyńiski, R., Holzman, B., Iordanova, A., Johnson, E., Kane, J. L., Katzy, J., Khan, N., Kucewicz, W., Kulinich, P., Kuo, C. M., Lin, W. T., Manly, S., McLeod, D., Michalowski, J., Mignerey, A. C., Mülmenstädt, J., Nouicer, R., Olszewski, A., Pak, R., Park, I. C., Pernegger, H., Rafelski, M., Rbeiz, M., Reed, C., Remsberg, L. P., Reuter, M., Roland, C., Roland, G., Rosenberg, L., Sagerer, J., Sarin, P., Sawicki, P., Skulski, W., Steadman, S. G., Steinberg, P., Stephans, G. S. F., Stodulski, M., Sukhanov, A., Tang, J-L., Teng, R., Trzupek, A., Vale, C., van Nieuwenhuizen, G. J., Verdier, R., Wadsworth, B., Wolfs, F. L. H., Wosiek, B., Woźniak, K., Wuosmaa, A. H., and Wyslouch, B.

Published
2003
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32. Results from the PHOBOS experiment at RHIC

Author

Back, B. B., Baker, M. D., Barton, D. S., Betts, R. R., Bindel, R., Budzanowski, A., Busza, W., Carroll, A., Decowski, M. P., Garcia, E., George, N., Gulbrandsen, K., Gushue, S., Halliwell, C., Heintzelman, G. A., Henderson, C., Hofman, D. J., Hołyński, R., Holzman, B., Johnson, E., Kane, J. L., Katzy, J., Khan, N., Kucewicz, W., Kulinich, P., Lin, W. T., Manly, S., McLeod, D., Michałowski, J., Mignerey, A. C., Mülmenstädt, J., Nouicer, R., Olszewski, A., Pak, R., Park, I. C., Pernegger, H., Reed, C., Remsberg, L. P., Reuter, M., Roland, C., Roland, G., Rosenberg, L., Sarin, P., Sawicki, P., Skulski, W., Steadman, S. G., Steinberg, P., Stephans, G. S. F., Stodulski, M., Sukhanov, A., Tang, J. -L., Teng, R., Trzupek, A., Vale, C., van Nieuwenhuizen, G. J., Verdier, R., Wadsworth, B., Wolfs, F. L. H., Wosiek, B., Woźniak, K., Wuosmaa, A. H., Wysłouch, B., and the PHOBOS Collaboration

Published
2002
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33. The PHOBOS experiment at RHIC

Author

Garcia, Edmundo, Back, B. B., Baker, M. D., Barton, D. S., Betts, R. R., Bindel, R., Budzanowski, A., Busza, W., Carroll, A., Decowski, M. P., George, N., Gulbrandsen, K., Gushue, S., Halliwell, C., Heintzelman, G. A., Henderson, C., Hofman, D. J., Hołyński, R., Holzman, B., Johnson, E., Kane, J. L., Katzy, J., Khan, N., Kucewicz, W., Kulinich, P., Lin, W. T., Manly, S., McLeod, D., Michałowski, J., Mignerey, A. C., Mülmenstädt, J., Nouicer, R., Olszewski, A., Pak, R., Park, I. C., Pernegger, H., Reed, C., Remsberg, L. P., Reuter, M., Roland, C., Roland, G., Rosenberg, L., Sarin, R., Sawicki, R., Skulski, W., Steadman, S. G., Steinberg, R., Stephans, G. S. F., Stodulski, M., Sukhanov, A., Tang, J. -L., Teng, R., Trzupek, A., Vale, C., van Nieuwenhuizen, G. J., Verdier, R., Wadsworth, B., Wolfs, F. L. H., Wosiek, B., Woźniak, K., Wuosmaa, A. H., and Wysłouch, B.

Published
2002
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34. Estrogen and testosterone have opposing effects on chronic cardiac remodeling and function in mice with myocardial infarction

Author

Cavasin, Maria A., Sankey, Steadman S., Yu, Ai-Li, Menon, Shreevidya, and Yang, Xiao-Ping

Subjects
Heart attack -- Physiological aspects, Estrogen -- Physiological aspects, Testosterone -- Physiological aspects, Hormones, Sex -- Physiological aspects, Biological sciences
Abstract

Premenopausal women are much less prone to develop cardiovascular disease than men of similar age, but this advantage no longer applies after menopause. We previously found that male mice have a significantly higher rate of cardiac rupture than females during the acute phase of myocardial infarction (MI); however, the effects of sexual hormones on chronic remodeling are unknown. We hypothesized that estrogen (E) may protect the heart from chronic remodeling and deterioration of function post-MI, whereas testosterone (T) may have adverse effects. Mice (4 wk old) of both genders were divided into four groups: female groups consisted of 1) sham ovariectomy (S-Ovx) + placebo (P) (S-Ovx + P), 2) S-Ovx + T, 3) Ovx + P, and 4) Ovx + T; and male groups consisted of 1) sham castration (S-Cas)+ P (S-Cas + P), 2) S-Cas + 17[beta]-estradiol (E), 3) Cas + P, and 4) Cas + E. MI was induced 6 wk later. Echocardiography was performed to assess cardiac function and left ventricular dimensions (LVD). Myocyte cross-sectional area (MCSA) was measured at the end of the study. In females, both testosterone and ovariectomy decreased ejection fraction (EF) and increased LVD, and when combined they aggravated cardiac function and remodeling further. Testosterone significantly increased MCSA. In males, castration or estrogen increased EF and reduced LVD, whereas castration significantly reduced MCSA. Our data suggest that estrogen prevents deterioration of cardiac function and remodeling after MI, but testosterone worsens cardiac dysfunction and remodeling and has a pronounced effect when estrogen levels are reduced. sexual hormones; cardiac dysfunction

Published
2003

35. Observation of the antimatter helium-4 nucleus

Author

Agakishiev, H., 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., Biritz, B., 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., Calderon, M., Cebra, D., Cendejas, R., Cervantes, M. C., Chajecki, Z., 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., Davila Leyva, A., De Silva, L. C., Debbe, R. R., Dedovich, T. G., Derevschikov, A. A., Derradi de Souza, R., Didenko, L., Djawotho, P., Dogra, S. M., Dong, X., Drachenberg, J. L., Draper, J. E., 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., Guertin, S. M., 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., Kurnadi, P., 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., Lisa, M. A., Liu, F., Liu, H., Liu, J., Ljubicic, T., Llope, W. J., Longacre, R. S., Love, W. A., 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., Matulenko, Yu. A., 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., Netrakanti, P. K., Nogach, L. V., Nurushev, S. B., Odyniec, G., Ogawa, A., Oh, K., Ohlson, A., Okorokov, V., Oldag, E. W., 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., 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., 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., Subba, N. L., Sumbera, M., Sun, X. M., Sun, Y., Sun, Z., Surrow, B., Svirida, D. N., Symons, T. J. M., Szanto de Toledo, A., 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., Tsai, O. D., Ullrich, T., Underwood, D. G., Van Buren, G., van Nieuwenhuizen, G., Vanfossen, J. A., Jr, Varma, R., Vasconcelos, G. M. S., Vasiliev, A. N., Videbaek, 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., Jr, Whitten 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., Zhou, W., Zhu, X., Zhu, Y. H., Zoulkarneev, R., and Zoulkarneeva, Y.

Published
2011
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37. Measurement of Møller scattering at 2.5 MeV

Author

Epstein, C. S., primary, Johnston, R., additional, Lee, S., additional, Bernauer, J. C., additional, Corliss, R., additional, Dow, K., additional, Fisher, P., additional, Friščić, I., additional, Hasell, D., additional, Milner, R. G., additional, Moran, P., additional, Steadman, S. G., additional, Wang, Y., additional, Dodge, J., additional, Ihloff, E., additional, Kelsey, J., additional, Vidal, C., additional, and Cooke, C. M., additional

Published
2020
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42. Prognosis and outcomes of patients with community-acquired pneumonia: a meta-analysis

Author

Fine, Michael J., Smith, Melanie A., Carson, Catherine A., Mutha, Sunita S., Sankey, Steadman S., Weissfeld, Lisa A., and Kapoor, Wishwa N.

Subjects
Nosocomial infections -- Prognosis, Pneumonia -- Prognosis
Abstract

Researchers used meta-analysis to evaluate 127 studies on community-acquired pneumonia (CAP) covering 33,148 patients that were published from 1966 to 1995. The overall mortality rate was 13.7%, but rates in individual studies ranged from 5.1% in hospitalized and ambulatory patients to 36.5% in an intensive care unit. Eleven factors were found to predict mortality and included male sex, chest pain, hypothermia, hypotension and pulmonary infiltrate. Most of these factors are known at the time of admission and could be used to predict mortality. Mortality was also associated with the type of bacterium involved, being highest in patients infected with Pseudomonas, Klebsiella, E. coli and Staphylococcus aureus. Only one-third of the studies reported any other complications of CAP and less than 10% reported on functional outcomes such as return to work or regular activities., Objective. - To systematically review the medical literature on the prognosis and outcomes of patients with community-acquired pneumonia (CAP). Data Sources. - A MEDLINE literature search of English-language articles involving human subjects and manual reviews of article bibliographies were used to identify studies of prognosis in CAP. Study Selection. - Review of 4573 citations revealed 122 articles (127 unique study cohorts) that reported medical outcomes in adults with CAP. Data Extraction. - Qualitative assessments of studies&apos; patient populations, designs, and patient outcomes were performed. Summary univariate odds ratios (ORs) and rate differences (RDs) and their associated 95% confidence intervals (CIs) were computed to estimate a summary effect size for the association of prognostic factors and mortality. Data Synthesis. - The overall mortality for the 33 148 patients in all 127 study cohorts was 13.7%, ranging from 5.1 % for the 2097 hospitalized and ambulatory patients (in six study cohorts) to 36.5% for the 788 intensive care unit patients (in 13 cohorts). Mortality varied by pneumonia etiology, ranging from less than 2% to greater than 30%. Eleven prognostic factors were significantly associated with, mortality using both summary ORs and RDs: male sex (OR=1.3; 95% CI, 1.2 to 1.4), pleuritic chest pain (OR=0.5; 95% CI, 0.3 to 0.8), hypothermia (OR=5.0; 95% CI, 2.4 to 10.4), systolic hypotension (OR=4.8; 95% CI, 2.8 to 8.3), tachypnea (OR=2.9; 95% CI, 1.7 to 4.9), diabetes mellitus (OR=1.3; 95% CI, 1.1 to 1.5), neoplastic disease (OR=2.8; 95% CI, 2.4 to 3. 1), neurologic disease (OR=4.6; 95% CI, 2.3 to 8.9), bacteremia (QR=2.8; 95% CI, 2.3 to 3.6), leukopenia (OR=2.5; 95% CI, 1.6 to 3.7), and multilobar radiographic pulmonary infiltrate (OR=3.1; 95% CI, 1.9 to 5.1). Assessments of other clinically relevant medical outcomes such as morbid complications (41 cohorts), symptoms resolution (seven cohorts), return to work or usual activities (five cohorts), or functional status (one cohort) were infrequently performed. Conclusions. - Mortality for patients hospitalized with CAP was high and was associated with characteristics of the study cohort, pneumonia etiology, and a variety of prognostic factors. Generalization of these findings to all patients with CAP should be made with caution because of insufficient published information on medical outcomes other than mortality in ambulatory patients.

Published
1996

47. Recent discoveries (2015-2016) at Cadir Hoyuk on the north central plateau

Author

Steadman, S. R., Şerifoğlu, T. E., McMahon, G., Selover, S., Hackley, L. D., Yıldırım, B., Lauricella, A. J., Arbuckle, B. S., Adcock, S. E., Tardio, K., Dinç, E., and Cassis, M.

Abstract

The Cadir Höyük mound is located in the Yozgat Province, approximately 16 km from the modern town of Sorgun. The site has been under excavation by members of the present team since 1994, following an intensive surface survey in 1993. The earliest documented occupation of the mound dates to 5200 cal. BC; the site was abandoned at some point in the 12th-13th centuries CE. Since 2012 the Cadir team has investigated virtually every period represented on the site, from the Late Chalcolithic through the Byzantine periods. The 2015 and 2016 seasons of work, the focus of the present article, continued this trend of complete coverage, with particular focus on the prehistoric (Late Chalcolithic) and Byzantine occupation. The second and first millennia BCE were also investigated, and an overview of some of these results are offered here. The last two seasons have been particularly helpful in allowing us to carefully phase the Late Chalcolithic town, which has manifested into an "upper" and "lower" component. The settlement phases demonstrate a changing strategy of town planning over the course of the fourth millennium. These two seasons have also yielded substantial results in our Byzantine occupation, allowing a better understanding of the architecture associated with the defensive wall that rings the mound summit, and insight into the occupation of the site in the centuries spanning the early second millennium CE.

Published
2017

48. Willingness to Pay for Quality of Life Technologies to Enhance Independent Functioning Among Baby Boomers and the Elderly Adults

Author

Judith T. Matthews, Richard Schulz, Laurel Person Mecca, K. Courtney, Annette DeVito Dabbs, Steadman S. Sankey, and Scott R. Beach

Subjects
Male, Gerontology, Cost effectiveness, Quality of life (healthcare), Willingness to pay, Humans, Marketing, Population Growth, Aged, Personal care, End user, Data Collection, General Medicine, Middle Aged, United States, Order (business), Quality of Life, Regression Analysis, Female, Meal preparation, Independent Living, Health Expenditures, Geriatrics and Gerontology, Psychology, Independent living, Research Article
Abstract

Purpose: We report the results of a study designed to assess whether and how much potential individual end users are willing to pay for Quality of Life Technologies (QoLTs) designed to enhance functioning and independence. Design and Methods: We carried out a web survey of a nationally representative sample of U.S. baby boomers (aged 45–64; N = 416) and older adults (aged 65 and greater, N = 114). Respondents were first instructed to assume that they needed help with kitchen activities/personal care and that technology was available to help with things like meal preparation/dressing, and then they were asked the most they would be willing to pay each month out of pocket for these technologies. Results: We modeled willingness to pay some (72% of respondents) versus none (28%), and the most people were willing to pay. Those willing to pay something were on average willing to pay a maximum of $40.30 and $45.00 per month for kitchen and personal care technology assistance, respectively. Respondents concerned about privacy or who were currently using assistive technology were less willing to pay. Respondents with higher incomes, who were Hispanic, or who perceived a higher likelihood of needing help in the future were more willing to pay. Implications: Consumers’ willingness to pay out of pocket for technologies to improve their well-being and independence is limited. In order to be widely adopted, QoLTs will have to be highly cost effective so that third party payers such as Medicare and private insurance companies are willing to pay for them.

Published
2013

50. Effective lactate clearance is associated with improved outcome in post-cardiac arrest patients

Author

Steadman S Sankey, Robert L. Sherwin, Michael W. Donnino, Ronny M. Otero, Joseph Miller, Charles R. Wira, Nikhil Goyal, Bram Dolcourt, and Manisha Loomba

Subjects
Male, medicine.medical_specialty, Resuscitation, Emergency Nursing, Sepsis, Intensive care, Emergency medical services, Humans, Medicine, Lactic Acid, Retrospective Studies, business.industry, Metabolic disorder, Retrospective cohort study, Emergency department, Middle Aged, Prognosis, medicine.disease, Cardiopulmonary Resuscitation, United States, Heart Arrest, Surgery, Survival Rate, Anesthesia, Lactic acidosis, Emergency Medicine, Female, Cardiology and Cardiovascular Medicine, business, Biomarkers, Follow-Up Studies
Abstract

Early, effective lactate clearance has been shown to be associated with improved mortality in patients with trauma, burns, and sepsis. We investigated whether early, high lactate clearance was associated with reduced mortality in post-cardiac arrest patients.We performed a retrospective analysis of post-cardiac arrest patients in an urban emergency department. Inclusion criteria included pre-hospital cardiac arrest patients over the age of 18. Exclusion criteria were traumatic arrest, successful resuscitation prior to the arrival of emergency medical services, and cardiac arrest in the presence of pre-hospital providers. Primary endpoints consisted of survival to 24h and survival to hospital discharge.A total of 79 patients were analyzed with a mean age of 64+/-17 and mean APACHE II score of 37.7+/-5. Of the 79 patients, 27 (34%) died within 24h and 66 (84%) died during the hospital course. The mean initial lactate level for the overall group was 15+/-5.2mmol/dl with a mean lactate of 14.4+/-5.1mmol/dl in the survivors and 16+/-5.3mmol/dl in the non-survivors (p0.05). Lactate clearance at both 6 and 12h was significantly higher for both 24-h and overall in-hospital survival (p0.05). A multivariable analysis showed that high lactate clearance at 12h was predictive of 24-h survival (p0.05).Early, effective lactate clearance is associated with decreased early and overall in-hospital mortality in post-cardiac arrest patients. These findings suggest that post-arrest tissue hypo-perfusion plays in an important role in early as well as overall mortality.

Published
2007

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