Nuclear shadowing and prompt photons in hadronic collisions at ultrarelativistic energies

Abstract

The production of prompt photons at high energies provides a direct probe of the dynamics of strong interactions. In particular, one expects that it could be used to constrain the behavior of the nuclear gluon distribution in pA and AA collisions. In this brief report, we investigate the influence of nuclear effects in the production of prompt photons and estimate the transverse momentum dependence of the nuclear ratios RpA= dσ(pA)dy d2pT/A dσ(pp)dy d2pT and RAA = dσ(AA)dy d2pT/A2 dσ(pp)dy d2pT at at energies currently available at the BNL Relativistic Heavy Ion Collider and CERN Large Hadron Collider.We demonstrate that the study of these observables can be useful in determining the magnitude of the shadowing and antishadowing effects in the nuclear gluon distribution.