gamma cross section in p plus p collisions at root s=200 GeV
Contribuinte(s) |
UNIVERSIDADE DE SÃO PAULO |
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Data(s) |
18/04/2012
18/04/2012
2010
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Resumo |
We report on a measurement of the gamma(1S + 2S + 3S) -> e(+)e(-) cross section at midrapidity in p + p collisions at root s = 200 GeV. We find the cross section to be 114 +/- 38(stat + fit)(-24)(+23)(syst) pb. Perturbative QCD calculations at next-to-leading order in the color evaporation model are in agreement with our measurement, while calculations in the color singlet model underestimate it by 2 sigma. Our result is consistent with the trend seen in world data as a function of the center-of-mass energy of the collision and extends the availability of gamma data to RHIC energies. The dielectron continuum in the invariant-mass range near the gamma is also studied to obtain a combined yield of e(+)e(-) pairs from the sum of the Drell-Yan process and b-(b) over bar production. RHIC RCF at BNL NERSC Center at LBNL Open Science Grid consortium U.S. DOE Office of Science U.S. NSF National Science Foundation Sloan Foundation Deutsche Forschungsgemeinschaft - DFG cluster of excellence ""Origin and Structure of the Universe'' of Germany Centre National de la Recherche Scientifique - CNRS/IN2P3 STFC EPSRC, United Kingdom FAPESP CNPq of Brazil MES Ministry of Education and Science of the Russian Federation National Natural Science Foundation of China (NNSFC) CAS of China MoST of China MoE of China GACR Grant Agency of the Academy of Sciences of the Czech Republic MSMT of the Czech Republic FOM of the Netherlands NWO of the Netherlands (DAE) Department of Atomic Energy, India (DST) Department of Science and Technology, India (CSIR) Council of Scientific and Industrial Research - India Polish Ministry of Science and Higher Education Korea Research Foundation (KRF) Ministry of Science, Education and Sports of the Republic Of Croatia MES Russian Ministry of Science and Technology RosAtom of Russia |
Identificador |
PHYSICAL REVIEW D, v.82, n.1, 2010 1550-7998 http://producao.usp.br/handle/BDPI/16296 10.1103/PhysRevD.82.012004 |
Idioma(s) |
eng |
Publicador |
AMER PHYSICAL SOC |
Relação |
Physical Review D |
Direitos |
restrictedAccess Copyright AMER PHYSICAL SOC |
Palavras-Chave | #NUCLEUS-NUCLEUS COLLISIONS #QUARK-GLUON PLASMA #J-PSI #SUPPRESSION #RESONANCES #DIMUON #Astronomy & Astrophysics #Physics, Particles & Fields |
Tipo |
article original article publishedVersion |