Impact parameter dependence of photon-photon interactions in relativistic heavy-ion collisions

Abstract

The Lorentz-boosted electromagnetic fields surrounding relativistic heavy ions with large charges can be treated as a flux of linearly polarized quasireal photons, which can interact via the photon-photon scattering to produce lepton antilepton pairs. Those photon-photon interactions can happen even in heavy-ion collisions with hadronic overlap, making an opportunity to probe the electromagnetic properties of the produced deconfined quark-gluon plasma. In this paper, we review the recent experimental progress of the impact parameter dependent photon-photon interactions in heavy-ion collisions, and discuss their essential role in probing the possible electromagnetic properties of quark-gluon plasma produced in hadronic heavy-ion collisions.