1998/07/06 by Adrian Dumitru, Dumitru, Adrian, Nils Hammon +2
Physics and Astronomy · #FOS: Physical sciences #High Energy Physics - Phenomenology (hep-ph) #High-Energy Particle Collisions Research #Nuclear Theory (nucl-th) #Particle physics theoretical and experimental studies #Quantum Chromodynamics and Particle Interactions #hep-ph #nucl-th
paper · pdf · doi:10.48550/arxiv.hep-ph/9807260
10 pages, 2 eps-figures, REVTEX. Some references added
openalex publication_date 1998/07/06 · arxiv created 1998/07/22 · arxiv updated 2009/11/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We discuss the transverse momentum distribution of thermal and prompt photons in ultrarelativistic heavy ion collisions. The prompt photons are mostly produced by fragmentation of quark jets (bremsstrahlung). If these quark jets suffer a large energy loss in heavy-ion reactions, prompt photons are significantly suppressed. Thermal electromagnetic radiation from the quark-gluon plasma and the hadron gas might then dominate the intermediate kT-range. In central Au+Au collisions at √(s)=200A GeV, and in the range 2 GeV < kT < 4 GeV, the inverse slope of the thermal radiation is 360-460 MeV, while that of the QCD photons is 500-1000 MeV. This large difference might allow to disentangle the various sources of direct photons experimentally. At √(s)=5.5A TeV, nuclear shadowing and quark-jet quenching suppresses the QCD-photons strongly for kT<5 GeV. Thermal radiation dominates in this kT-region.