Speaker
Description
Dileptons are penetrating probes for the early-stage dynamics of the quark-gluon plasma (QGP). The polarization of dileptons encodes detailed information about their production mechanism. This study presents an integrated and realistic framework for calculating dilepton polarization signatures using the photon spectral function of a finite-temperature QCD plasma. Combining virtual photon spectral functions with a multi-stage iEBE-MUSIC hydrodynamic simulation of Pb+Pb collisions at the LHC, we focus on invariant masses < 5 GeV and confirm significant differences in polarization coefficients between next-to-leading order (NLO) [1] and leading order (LO) in the strong coupling [2]. We examine how these coefficients vary across reference frames and include the contribution from the NLO Drell-Yan process, an irreducible pQCD background [3]. Finally, we demonstrate how non-equilibrium modifications of the photon spectral function can impact dilepton polarization signatures, and present results including shear-viscous corrections to the polarization observables [4].