Unravelling γγ dileptons in central relativistic heavy ion collisions

Abstract

Using an impact parameter formulation, differential production probabilities for γγ dileptons in central relativistic heavy ion collisions at RHIC and LHC energies are calculated and compared to Drell-Yan and thermal ones. The angular distributions of the leptons give a handle for the discrimination. Nuclear stopping leads, apart from Bremsstrahlung pair production, to a modification of the pure γγ dilepton production. These modifications are studied in a simple model and are found to be of minor influence.