Thermal Dileptons at LHC

TL;DR

This paper predicts dilepton spectra in high-energy Pb-Pb collisions at LHC, highlighting the roles of hadronic and quark-gluon plasma emissions, with a focus on the impact of open-charm hadron decays.

Contribution

It provides a comprehensive prediction of dilepton spectra including in-medium effects and heavy-flavor decay contributions at LHC energies.

Findings

Low-mass region dominated by hadronic in-medium spectral functions.

Intermediate-mass region primarily from thermal radiation of QGP.

Open-charm decays significantly influence the dilepton spectra.

Abstract

We predict dilepton invariant-mass spectra for central 5.5 ATeV Pb-Pb collisions at LHC. Hadronic emission in the low-mass region is calculated using in-medium spectral functions of light vector mesons within hadronic many-body theory. In the intermediate-mass region thermal radiation from the Quark-Gluon Plasma, evaluated perturbatively with hard-thermal loop corrections, takes over. An important source over the entire mass range are decays of correlated open-charm hadrons, rendering the nuclear modification of charm and bottom spectra a critical ingredient.