Photoproduction of J/psi and of high mass e(+)e(-) in ultra-peripheral Au plus Au collisions at root s(NN)=200 GeV
Contribuinte(s) |
UNIVERSIDADE DE SÃO PAULO |
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Data(s) |
20/10/2012
20/10/2012
2009
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Resumo |
We present the first measurement of photoproduction of J/psi and of two-photon production of high-mass e(+)e(-) pairs in electromagnetic (or ultra-peripheral) nucleus-nucleus interactions, using Au + Au data at root s(NN) = 200 GeV. The events are tagged with forward neutrons emitted following Coulomb excitation of one or both Au* nuclei. The event sample consists of 28 events with m(e+e-) > 2 GeV/c(2) with zero like-sign background. The measured cross sections at midrapidity of d sigma/dy (J/psi + Xn, y = 0) = 76 +/- 33 (stat) +/- 11 (syst) pb and d(2)sigma /dm dy (e(+) e(-) + Xn, y = 0) = 86 +/- 23(stat) +/- 16(syst) mu b/ (GeV/c(2)) for m(e+e-) epsilon vertical bar 2.0, 2.8 vertical bar GeV/c(2) have been compared and found to be consistent with models for photoproduction of J/psi and QED based calculations of two-photon production of e(+)e(-) pairs. (C) 2009 Elsevier B.V. All rights reserved. Office of Nuclear Physics in DOE Office of Science and NSF (USA) U.S. National Science Foundation (NSF) U.S. Department of Energy (DOE) MEXT MEXT Japan Society for the Promotion of Science (JSPS) JSPS Oapan Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) CNPq Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) FAPESP (Brazil) Natural Science Foundation of China (NSFC) NSFC Natural Science Foundation (China) IN2P3/CNRS IN2P3/CNRS CEA (France) Commissariat à l énergie atomique et aux énergies alternatives (CEA) BIVIBF, DAAD BIVIBF Deutscher Akademischer Austauschdienst (DAAD) Alexander von Humboldt Foundation (AvH) Alexander von Humboldt Foundation - AvH (Germany) Országos Tudományos Kutatási Alapprogramok (OTKA) OTKA (Hungary) DAE (India) Department of Atomic Energy of India (DAE) ISF (Israel) ISF (Israel) KRF KRF KOSEF (Korea) KOSEF (Korea) MES MES RAS RAS FAAE (Russia) FAAE (Russia) VR VR KAW (Sweden) KAW (Sweden) US CRDF for the FSU US CRDF for the FSU US-Hungarian NSF-OTKA-MTA US-Hungarian NSF-OTKA-MTA US-Israel BSF US-Israel BSF |
Identificador |
PHYSICS LETTERS B, v.679, n.4, p.321-329, 2009 0370-2693 http://producao.usp.br/handle/BDPI/29219 10.1016/j.physletb.2009.07.061 |
Idioma(s) |
eng |
Publicador |
ELSEVIER SCIENCE BV |
Relação |
Physics Letters B |
Direitos |
restrictedAccess Copyright ELSEVIER SCIENCE BV |
Palavras-Chave | #HEAVY-ION COLLISIONS #DETECTORS #ENERGIES #DENSITY #PHYSICS #MESONS #Physics, Multidisciplinary |
Tipo |
article original article publishedVersion |