Centrality dependence of dilepton production via γγ processes from Wigner distributions of photons in nuclei

Abstract

Abstract We propose a new complete method, based on the Wigner distributions of photons, how to calculate differential distributions of dileptons created via photon-photon fusion in semicentral ( b 2 R A ) AA collisions. The formalism is used to calculate different distributions of invariant mass, dilepton transverse momentum and acoplanarity for different regions of centrality. The results of calculation are compared with recent STAR, ALICE and ATLAS experimental data. Very good agreement with the data is achieved without free parameters and without including additional mechanisms such as a possible rescattering of leptons in the quark-gluon plasma.