Nuclear modification of heavy flavor decayed dielectrons in relativistic heavy-ion collisions

TL;DR

This paper investigates how heavy quark interactions with the quark-gluon plasma affect dielectron spectra and correlations, revealing medium effects that influence temperature extraction and pair angular distributions in high-energy nuclear collisions.

Contribution

It introduces a comprehensive model combining Boltzmann transport and hybrid hadronization to study medium modifications of heavy flavor dielectrons in relativistic heavy-ion collisions.

Findings

Heavy quark energy loss softens dielectron invariant mass spectrum.

Medium effects lead to higher extracted QGP temperatures.

Angular correlations are sensitive to heavy quark-medium interactions.

Abstract

Dielectrons from heavy flavor hadron decays not only constitute a crucial background to their thermal spectrum in high-energy nuclear collisions, from which the temperature of the quark-gluon plasma (QGP) is extracted, but also provide a valuable probe of heavy quark interactions with the QGP. Using a linear Boltzmann transport (LBT) model to describe heavy quark evolution inside the QGP and a hybrid fragmentation-coalescence model for their hadronization, we find heavy quark energy loss softens the invariant mass spectrum of their decayed dielectrons and yields a higher value of the extracted QGP temperature, while coalescence hardens the spectrum and yields a lower value. Taking into account full medium effects leads to higher values of the extracted temperature than using vacuum baselines of heavy flavor decayed dielectrons in analyzing the experimental data. In addition, we find the angular correlations between dielectron pairs are sensitive to heavy quark interactions with the QGP: the radial flow of the QGP enhances the near-side correlations, and scatterings between heavy quarks and the QGP broaden the away-side correlations, with elastic and string interactions playing a dominant role.