Dilepton production from SIS to LHC energies

TL;DR

This paper investigates dilepton production across a wide energy range from SIS to LHC using the PHSD model, revealing in-medium effects at lower energies and clear signatures of partonic degrees of freedom at higher energies.

Contribution

It introduces a comprehensive analysis of dilepton production incorporating explicit partonic degrees-of-freedom within the PHSD framework across multiple collision energies.

Findings

In-medium vector-meson effects are visible at SIS to SPS energies.

Partonic contributions dominate dilepton yields at SPS and RHIC energies.

Dilepton signals of the quark-gluon plasma are evident at top SPS energies and become more pronounced at RHIC and LHC.

Abstract

We study e+e- pair production in proton-proton and in nucleus-nucleus collisions from SIS to LHC energies within the parton-hadron-string dynamics (PHSD) approach which incorporates explicit partonic degrees-of-freedom in terms of strongly interacting quasiparticles (quarks and gluons) in line with an equation-of-state from lattice QCD as well as the dynamical hadronization and hadronic collision dynamics in the final reaction phase. We find a visible in-medium effect in the low mass dilepton sector from dynamical vector-meson spectral functions from SIS to SPS energies whereas at RHIC and LHC energies such medium effects become more moderate. In the intermediate mass regime from 1.1 to 3 GeV pronounced traces of the partonic degrees of freedom are found at SPS and RHIC energies which superseed the hadronic (multi-meson) channels as well as the correlated and uncorrelated semi-leptonic D-meson decays. The dilepton production from the strongly interacting quark gluon plasma (sQGP) becomes already visible at top SPS energies and more pronounced at RHIC and LHC energies.