Direct photon production of d+A and A+A collisions at RHIC

Journal Article · Tue Jan 01 04:00:00 EST 2008 · European Physical Journal. C, Particles and Fields

OSTI ID:960895

Zhang, Benwei ^[1]; Vitev, Ivan ^[1]

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1. Los Alamos National Laboratory

Direct photon productions in minimum bias d+Cu and d+Au and central Cu+Cu and Au+Au at center of mass energies {radical}s = 62.4 GeV and 200GeV at RHIC are investigated systematically by taking into account jet quenching effect, medium-induced photon bremsstrahlung and jet-photon conversion in the hot QGP as well as known cold nuclear matter effects such as the isospin effect, the Cronin effect, shadowing effect, EMC effect and cold nuclear matter energy loss. It is shown that at high p{sub T} the nuclear modification factor for direct photon R{sub AA}(p{sub T}) is suppressed and dominated by cold nuclear matter effects, and there is no large enhancement due to medium-induced photon bremsstrahlung and jet-photon conversion in the hot QGP. Comparison of numerical simulations with experimental data rules out large Cronin enhancement and incoherent photon emission in medium, though large error bars in currently experimental data can not provide tight constraints on other nuclear matter effects.

• Research Organization: Los Alamos National Laboratory (LANL)
• Sponsoring Organization: DOE
• DOE Contract Number: AC52-06NA25396
• OSTI ID: 960895
• Report Number(s): LA-UR-08-06396; LA-UR-08-6396
• Journal Information: European Physical Journal. C, Particles and Fields, Journal Name: European Physical Journal. C, Particles and Fields; ISSN 1434-6044
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
BREMSSTRAHLUNG
COLLISIONS
CONVERSION
EMC EFFECT
ENERGY
ERRORS
GLUONS
HEAVY ION REACTIONS
ION COLLISIONS
ISOSPIN
JETS
MASS
MODIFICATIONS
NUCLEAR MATTER
PHOTON EMISSION
PHOTONS
PRODUCTION
QUARK MATTER
QUARKS
QUENCHING