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Enhanced production of direct photons in Au+Au collisions at sqrt(s_NN)=200 GeV and implications for the initial temperature

SYSNO ASEP	0370231
Document Type	J - Journal Article
R&D Document Type	Journal Article
Subsidiary J	Článek ve WOS
Title	Enhanced production of direct photons in Au+Au collisions at sqrt(s_NN)=200 GeV and implications for the initial temperature
Author(s)	Adare, A. (US) Afanasiev, S. (RU) Aidala, C. (US) Kubart, J. (CZ) Mašek, L. (CZ) Mikeš, P. (CZ) Tomášek, Lukáš (FZU-D)_{RID, ORCID} Vrba, Václav (FZU-D)_{RID, ORCID}
Source Title	Physical Review Letters. - : American Physical Society - ISSN 0031-9007 Roč. 104, č. 13 (2010), "132301-1"-"132301-6"
Number of pages	6 s.
Language	eng - English
Country	US - United States
Keywords	p p: colliding beams ; nucleus nucleus: colliding beams ; scattering: heavy ion ; photon: direct production ; photon: yield ; PHENIX
Subject RIV	BF - Elementary Particles and High Energy Physics
R&D Projects	LC527 GA MŠMT - Ministry of Education, Youth and Sports (MEYS)
	LA08015 GA MŠMT - Ministry of Education, Youth and Sports (MEYS)
CEZ	AV0Z10100502 - FZU-D (2005-2011)
UT WOS	000276260800011
DOI	10.1103/PhysRevLett.104.132301
Annotation	The production of low mass e+e- pairs for m_{e+e-} < 300 MeV/c^2 and 1 < p_T <5 GeV/c is measured in p+p and Au+Au collisions at sqrt(s_NN)=200 GeV. Enhanced yield above hadronic sources is observed. Treating the excess as internal conversions, the invariant yield of direct photons is deduced. In central Au+Au collisions, the excess of direct photon yield over p+p is exponential in transverse momentum, with inverse slope T = 221 +/- 19 (stat) +/- 19 (syst) MeV. Hydrodynamical models with initial temperatures ranging from 300--600 MeV at times of ~ 0.6 - 0.15 fm/c after the collision are in qualitative agreement with the data. Lattice QCD predicts a phase transition to quark gluon plasma at ~ 170 MeV.
Workplace	Institute of Physics
Contact	Kristina Potocká, potocka@fzu.cz, Tel.: 220 318 579
Year of Publishing	2012

Number of the records: 1