UNRAVELING GAMMA-GAMMA DILEPTONS IN CENTRAL RELATIVISTIC HEAVY-ION COLLISIONS

Using an impact parameter formulation, differential production probabilities for gammagamma 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 gammagamma dilepton production. These modifications are studied in a simple model and are found to be of minor influence.