TY  - INPR
A1  - Hammon, Nils
A1  - Dumitru, Adrian Bogdan
A1  - Stöcker, Horst
A1  - Greiner, Walter
T1  - Nuclear shadowing effects on prompt photons at RHIC and LHC
N2  - The transverse momentum distribution of prompt photons coming from the very early phase of ultrarelativistic heavy ion collisions for the RHIC and LHC energies is calculated by means of perturbative QCD. We calculate the single photon cross section (A + B -> gamma + X) by taking into account the partonic sub processes q + q -> gamma + g and q + g -> gamma + q as well as the Bremsstrahlung corrections to those processes. We choose a lower momentum cut-off k0 = 2 GeV separating the soft physics from perturbative QCD. We compare the results for those primary collisions with the photons produced in reactions of the thermalized secondary particles, which are calculated within scaling hydrodynamics. The QCD processes are taken in leading order. Nuclear shadowing corrections, which alter the involved nuclear structure functions are explicitly taken into account and compared to unshadowed results. Employing the GRV parton distribution parametrizations we find that at RHIC prompt QCD-photons dominate over the thermal radiation down to transverse momenta kT ≈ 2 GeV. At LHC, however, thermal radiation from the QGP dominates for photon transverse momenta kT ≤ 5 GeV, if nuclear shadowing effects on prompt photon production are taken into account.
KW  - Kollisionen schwerer Ionen
KW  - LHC
KW  - Quark-Gluon Plasma
KW  - QGP
KW  - Quanten Chromodynamik
KW  - Quanten Chromodynamic
KW  - LHC
KW  - quark-gluon plasma
KW  - QGP
KW  - heavy ion collisions
Y1  - 2005
UR  - http://publikationen.ub.uni-frankfurt.de/frontdoor/index/index/docId/3068
UR  - https://nbn-resolving.org/urn:nbn:de:hebis:30-23246
ER  -