Virtual photon polarization and dilepton anisotropy in relativistic nucleus–nucleus collisions

Publication date: 10 July 2018Source: Physics Letters B, Volume 782Author(s): Enrico Speranza, Amaresh Jaiswal, Bengt FrimanAbstractThe polarization of virtual photons produced in relativistic nucleus–nucleus collisions provides information on the conditions in the emitting medium. In a hydrodynamic framework, the resulting angular anisotropy of the dilepton final state depends on the flow as well as on the transverse momentum and invariant mass of the photon. We illustrate these effects in dilepton production from quark–antiquark annihilation in the QGP phase and π+π− annihilation in the hadronic phase for a static medium in global equilibrium and for a longitudinally expanding system.

Source: Physics Letters B - July 10, 2018 Category: Physics Source Type: research