Detailed measurement of the e(+)e(-) pair continuum in p plus p and Au plus Au collisions at root s(NN)=200 GeV and implications for direct photon production

Autoria(s): ADARE, A.; AFANASIEV, S.; AIDALA, C.; AJITANAND, N. N.; AKIBA, Y.; AL-BATAINEH, H.; ALEXANDER, J.; AL-JAMEL, A.; AOKI, K.; APHECETCHE, L.; ARMENDARIZ, R.; ARONSON, S. H.; ASAI, J.; ATOMSSA, E. T.; AVERBECK, R.; AWES, T. C.; AZMOUN, B.; BABINTSEV, V.; BAKSAY, G.; BAKSAY, L.; BALDISSERI, A.; BARISH, K. N.; BARNES, P. D.; BASSALLECK, B.; BATHE, S.; BATSOULI, S.; BAUBLIS, V.; BAUER, F.; BAZILEVSKY, A.; BELIKOV, S.; BENNETT, R.; BERDNIKOV, Y.; BICKLEY, A. A.; BJORNDAL, M. T.; BOISSEVAIN, J. G.; BOREL, H.; BOYLE, K.; BROOKS, M. L.; BROWN, D. S.; BUCHER, D.; BUESCHING, H.; BUMAZHNOV, V.; BUNCE, G.; BURWARD-HOY, J. M.; BUTSYK, S.; CAMPBELL, S.; CHAI, J-S.; CHANG, B. S.; CHARVET, J-L.; CHERNICHENKO, S.; CHIBA, J.; CHI, C. Y.; CHIU, M.; CHOI, I. J.; CHUJO, T.; CHUNG, P.; CHURYN, A.; CIANCIOLO, V.; CLEVEN, C. R.; COBIGO, Y.; COLE, B. A.; COMETS, M. P.; CONSTANTIN, P.; CSANAD, M.; CSORGO, T.; DAHMS, T.; DAS, K.; DAVID, G.; DEATON, M. B.; DEHMELT, K.; DELAGRANGE, H.; DENISOV, A.; D'ENTERRIA, D.; DESHPANDE, A.; DESMOND, E. J.; Dietzsch, Olacio; DION, A.; Donadelli, Marisílvia; DRACHENBERG, J. L.; DRAPIER, O.; DREES, A.; DUBEY, A. K.; DURUM, A.; DZHORDZHADZE, V.; EFREMENKO, Y. V.; EGDEMIR, J.; ELLINGHAUS, F.; EMAM, W. S.; ENOKIZONO, A.; EN'YO, H.; ESPAGNON, B.; ESUMI, S.; EYSER, K. O.; FIELDS, D. E.; FINGER JR., M.; FINGER, M.; FLEURET, F.; FOKIN, S. L.; FORESTIER, B.; FRAENKEL, Z.; FRANTZ, J. E.; FRANZ, A.; FRAWLEY, A. D.; FUJIWARA, K.; FUKAO, Y.; FUNG, S-Y.; FUSAYASU, T.; GADRAT, S.; GARISHVILI, I.; GASTINEAU, F.; GERMAIN, M.; GLENN, A.; GONG, H.; GONIN, M.; GOSSET, J.; GOTO, Y.; CASSAGNAC, R. Granier de; GRAU, N.; GREENE, S. V.; PERDEKAMP, M. Grosse; GUNJI, T.; GUSTAFSSON, H-A; HACHIYA, T.; HENNI, A. Hadj; HAEGEMANN, C.; HAGGERTY, J. S.; HAGIWARA, M. N.; HAMAGAKI, H.; HAN, R.; HARADA, H.; HARTOUNI, E. P.; HARUNA, K.; HARVEY, M.; HASLUM, E.; HASUKO, K.; HAYANO, R.; HEFFNER, M.; HEMMICK, T. K.; HESTER, T.; HEUSER, J. M.; HE, X.; HIEJIMA, H.; HILL, J. C.; HOBBS, R.; HOHLMANN, M.; HOLMES, M.; HOLZMANN, W.; HOMMA, K.; HONG, B.; HORAGUCHI, T.; HORNBACK, D.; HUR, M. G.; ICHIHARA, T.; IMAI, K.; INABA, M.; INOUE, Y.; ISENHOWER, D.; ISENHOWER, L.; ISHIHARA, M.; ISOBE, T.; ISSAH, M.; ISUPOV, A.; JACAK, B. V.; JIA, J.; JIN, J.; JINNOUCHI, O.; JOHNSON, B. M.; JOO, K. S.; JOUAN, D.; KAJIHARA, F.; KAMETANI, S.; KAMIHARA, N.; KAMIN, J.; KANETA, M.; KANG, J. H.; KANOU, H.; KAWAGISHI, T.; KAWALL, D.; KAZANTSEV, A. V.; KELLY, S.; KHANZADEEV, A.; KIKUCHI, J.; KIM, D. H.; KIM, D. J.; KIM, E.; KIM, Y-S.; KINNEY, E.; KISS, A.; KISTENEV, E.; KIYOMICHI, A.; KLAY, J.; KLEIN-BOESING, C.; KOCHENDA, L.; KOCHETKOV, V.; KOMKOV, B.; KONNO, M.; KOTCHETKOV, D.; KOZLOV, A.; KRAL, A.; KRAVITZ, A.; KROON, P. J.; KUBART, J.; KUNDE, G. J.; KURIHARA, N.; KURITA, K.; KWEON, M. J.; KWON, Y.; KYLE, G. S.; LACEY, R.; LAI, Y-S.; LAJOIE, J. G.; LEBEDEV, A.; BORNEC, Y. Le; LECKEY, S.; LEE, D. M.; LEE, M. K.; LEE, T.; LEITCH, M. J.; Leite, Marco Aurelio Lisboa; Lenzi, Bruno Rodrigues; LIM, H.; LISKA, T.; LITVINENKO, A.; LIU, M. X.; LI, X.; LI, X. H.; LOVE, B.; LYNCH, D.; MAGUIRE, C. F.; MAKDISI, Y. I.; MALAKHOV, A.; MALIK, M. D.; MANKO, V. I.; MAO, Y.; MASEK, L.; MASUI, H.; MATATHIAS, F.; MCCAIN, M. C.; MCCUMBER, M.; MCGAUGHEY, P. L.; MIAKE, Y.; MIKES, P.; MIKI, K.; MILLER, T. E.; MILOV, A.; MIODUSZEWSKI, S.; MISHRA, G. C.; MISHRA, M.; MITCHELL, J. T.; MITROVSKI, M.; MORREALE, A.; MORRISON, D. P.; MOSS, J. M.; MOUKHANOVA, T. V.; MUKHOPADHYAY, D.; MURATA, J.; NAGAMIYA, S.; NAGATA, Y.; NAGLE, J. L.; NAGLIS, M.; NAKAGAWA, I.; NAKAMIYA, Y.; NAKAMURA, T.; NAKANO, K.; NEWBY, J.; NGUYEN, M.; NORMAN, B. E.; NOUICER, R.; NYANIN, A. S.; NYSTRAND, J.; O'BRIEN, E.; ODA, S. X.; OGILVIE, C. A.; OHNISHI, H.; OJHA, I. D.; OKADA, H.; OKADA, K.; OKA, M.; OMIWADE, O. O.; OSKARSSON, A.; OTTERLUND, I.; OUCHIDA, M.; OZAWA, K.; PAK, R.; PAL, D.; PALOUNEK, A. P. T.; PANTUEV, V.; PAPAVASSILIOU, V.; PARK, J.; PARK, W. J.; PATE, S. F.; PEI, H.; PENG, J-C.; PEREIRA, H.; PERESEDOV, V.; PERESSOUNKO, D. Yu.; PINKENBURG, C.; PISANI, R. P.; PURSCHKE, M. L.; PURWAR, A. K.; QU, H.; RAK, J.; RAKOTOZAFINDRABE, A.; RAVINOVICH, I.; READ, K. F.; REMBECZKI, S.; REUTER, M.; REYGERS, K.; RIABOV, V.; RIABOV, Y.; ROCHE, G.; ROMANA, A.; ROSATI, M.; ROSENDAHL, S. S. E.; ROSNET, P.; RUKOYATKIN, P.; RYKOV, V. L.; RYU, S. S.; SAHLMUELLER, B.; SAITO, N.; SAKAGUCHI, T.; SAKAI, S.; SAKATA, H.; SAMSONOV, V.; SATO, H. D.; SATO, S.; SAWADA, S.; SEELE, J.; SEIDL, R.; SEMENOV, V.; SETO, R.; SHARMA, D.; SHEA, T. K.; SHEIN, I.; SHEVEL, A.; SHIBATA, T-A.; SHIGAKI, K.; SHIMOMURA, M.; SHOHJOH, T.; SHOJI, K.; SICKLES, A.; Silva, Cesar Luiz da; SILVERMYR, D.; SILVESTRE, C.; SIM, K. S.; SINGH, C. P.; SINGH, V.; SKUTNIK, S.; SLUNECKA, M.; SMITH, W. C.; SOLDATOV, A.; SOLTZ, R. A.; SONDHEIM, W. E.; SORENSEN, S. P.; SOURIKOVA, I. V.; STALEY, F.; STANKUS, P. W.; STENLUND, E.; STEPANOV, M.; STER, A.; STOLL, S. P.; SUGITATE, T.; SUIRE, C.; SULLIVAN, J. P.; SZIKLAI, J.; TABARU, T.; TAKAGI, S.; Takagui, Emi Marcia; TAKETANI, A.; TANAKA, K. H.; TANAKA, Y.; TANIDA, K.; TANNENBAUM, M. J.; TARANENKO, A.; TARJAN, P.; THOMAS, T. L.; TOGAWA, M.; TOIA, A.; TOJO, J.; TOMASEK, L.; TORII, H.; TOWELL, R. S.; TRAM, V-N.; TSERRUYA, I.; TSUCHIMOTO, Y.; TULI, S. K.; TYDESJO, H.; TYURIN, N.; VALE, C.; VALLE, H.; HECKE, H. W. van; VELKOVSKA, J.; VERTESI, R.; VINOGRADOV, A. A.; VIRIUS, M.; VRBA, V.; VZNUZDAEV, E.; WAGNER, M.; WALKER, D.; WANG, X. R.; WATANABE, Y.; WESSELS, J.; WHITE, S. N.; WILLIS, N.; WINTER, D.; WOODY, C. L.; WYSOCKI, M.; XIE, W.; YAMAGUCHI, Y. L.; YANOVICH, A.; YASIN, Z.; YING, J.; YOKKAICHI, S.; YOUNG, G. R.; YOUNUS, I.; YUSHMANOV, I. E.; ZAJC, W. A.; ZAUDTKE, O.; ZHANG, C.; ZHOU, S.; ZIMANYI, J.; ZOLIN, L.
Contribuinte(s)

UNIVERSIDADE DE SÃO PAULO
Data(s)

18/04/2012

18/04/2012

2010
Resumo

PHENIX has measured the e(+)e(-) pair continuum in root s(NN) = 200 GeV Au+Au and p+p collisions over a wide range of mass and transverse momenta. The e(+)e(-) yield is compared to the expectations from hadronic sources, based on PHENIX measurements. In the intermediate-mass region, between the masses of the phi and the J/psi meson, the yield is consistent with expectations from correlated c (c) over bar production, although other mechanisms are not ruled out. In the low-mass region, below the phi, the p+p inclusive mass spectrum is well described by known contributions from light meson decays. In contrast, the Au+Au minimum bias inclusive mass spectrum in this region shows an enhancement by a factor of 4.7 +/- 0.4(stat) +/- 1.5(syst) +/- 0.9(model). At low mass (m(ee) < 0.3 GeV/c(2)) and high p(T) (1 < p(T) < 5 GeV/c) an enhanced e(+)e(-) pair yield is observed that is consistent with production of virtual direct photons. This excess is used to infer the yield of real direct photons. In central Au+Au collisions, the excess of the direct photon yield over the p+p is exponential in p(T), with inverse slope T = 221 +/- 19(stat) +/- 19(syst) MeV. Hydrodynamical models with initial temperatures ranging from T(init) similar or equal to 300-600 MeV at times of 0.6-0.15 fm/c after the collision are in qualitative agreement with the direct photon data in Au+Au. For low p(T) < 1 GeV/c the low-mass region shows a further significant enhancement that increases with centrality and has an inverse slope of T similar or equal to 100 MeV. Theoretical models underpredict the low-mass, low-p(T) enhancement.

Office of Nuclear Physics in the Office of Science of the Department of Energy (DOE)

National Science Foundation (NSF)

Abilene Christian University Research Council

Research Foundation of SUNY

Dean of the College of Arts and Sciences, Vanderbilt University (USA)

Ministry of Education, Culture, Sports, Science, and Technology (MEXT), Japan

JSPS - Japan Society for the Promotion of Science (Japan)

Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq) and Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP) (Brazil)

NSFC Natural Science Foundation of China

MSMT Ministry of Education, Youth and Sports (Czech Republic)

Centre National de la Recherche Scientifique - CNRS

(CNRS/IN2P3) Commissariat a l'Energie Atomique, and Institut National de Physique Nucleaire et de Physique des Particules (France)

BMBF - Ministry of Industry, Science and Tekhnologies, Bundesministerium fur Bildung und Forschung, Deutscher Akademischer Austausch Dienst, and Alexander von Humboldt Stiftung (Germany)

Hungarian National Science Fund, OTKA (Hungary)

(DAE) Department of Atomic Energy, India

ISF - Israel Science Foundation (Israel)

National Research Foundation (NRF), Korea

MES Ministry of Education and Science, Russia Academy of Sciences, Federal Agency of Atomic Energy (Russia)

VR and the Wallenberg Foundation (Sweden)

CRDF US Civilian Research and Development Foundation for the Independent States of the Former Soviet Union

US-Hungarian NSF-OTKA-MTA

(BSF) U.S.-Israel Binational Science Foundation
Identificador

PHYSICAL REVIEW C, v.81, n.3, 2010

0556-2813

http://producao.usp.br/handle/BDPI/16079

10.1103/PhysRevC.81.034911

http://dx.doi.org/10.1103/PhysRevC.81.034911
Idioma(s)

eng
Publicador

AMER PHYSICAL SOC
Relação

Physical Review C
Direitos

restrictedAccess

Copyright AMER PHYSICAL SOC
Palavras-Chave #HEAVY-ION COLLISIONS #NUCLEUS-NUCLEUS COLLISIONS #SUPER-PROTON SYNCHROTRON #MASS ELECTRON PAIRS #QUARK-GLUON PLASMA #LIGHT MESONS #CERN-SPS #DILEPTON PRODUCTION #PHENIX EXPERIMENT #DIMUON PRODUCTION #Physics, Nuclear
Tipo

article

original article

publishedVersion
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