Analysis of dilepton production in Au+Au collisions at sqrt(s_NN)=200 GeV within the Parton-Hadron-String Dynamics (PHSD) transport approach

TL;DR

This paper employs the PHSD transport approach to analyze dilepton production in Au+Au collisions at 200 GeV, highlighting the role of partonic interactions and comparing results with experimental data.

Contribution

It introduces a comprehensive off-shell transport model that includes partonic and hadronic phases, providing detailed predictions for dilepton yields in heavy-ion collisions.

Findings

Partonic channels significantly contribute to dilepton production.

The model reproduces PHENIX data within uncertainties.

Predictions for STAR detector acceptance are provided.

Abstract

We address dilepton production in Au+Au collisions at sqrt(s_NN)=200 GeV by employing the parton-hadron-string dynamics (PHSD) off-shell transport approach. Within the PHSD one goes beyond the quasiparticle approximation by solving generalized transport equations on the basis of the off-shell Kadanoff-Baym equations for the Green's functions in the phase-space representation. The approach consistently describes the full evolution of a relativistic heavy-ion collision from the initial hard scatterings and string formation through the dynamical deconfinement phase transition to the quark-gluon plasma (QGP) as well as hadronization and to the subsequent interactions in the hadronic phase. {With partons described in the PHSD by the dynamical quasiparticle model (DQPM) - matched to reproduce lattice QCD results in thermodynamic equilibrium} - we calculate, in particular, the dilepton radiation from partonic interactions through the reactions q+qbar->gamma^*, q+qbar->gamma^*+g and q+g->gamma^*+q (qbar+g->gamma^*+qbar) in the early stage of relativistic heavy-ion collisions. By comparing our results to the data from the PHENIX Collaboration, we study the relative importance of different dilepton production mechanisms and point out the regions in phase space where partonic channels are dominant. Furthermore, explicit predictions are presented for dileptons within the acceptance of the STAR detector system and compared to the preliminary data.