Dynamical collisional energy loss and transport properties of on- and off-shell heavy quarks in vacuum and in the Quark Gluon Plasma

TL;DR

This paper evaluates the energy loss and transport properties of heavy quarks in vacuum and Quark Gluon Plasma, considering on-shell and off-shell particles, to better understand their microscopic dynamics in heavy-ion collisions.

Contribution

It introduces a comprehensive calculation of heavy quark transport coefficients including finite mass and width effects in both vacuum and QGP environments.

Findings

Finite parton mass and width significantly affect heavy quark transport properties.

Results provide essential inputs for microscopic modeling of heavy flavor dynamics in QGP.

The study compares on-shell and off-shell particle interactions using different cross sections.

Abstract

In this study we evaluate the dynamical collisional energy loss of heavy quarks, their interaction rate as well as the different transport coefficients (drag and diffusion coefficients, $\hat{q}$, etc). We calculate these different quantities for i) perturbative partons (on-shell particles in the vacuum with fixed and running coupling) and ii) for dynamical quasi-particles (off-shell particles in the QGP medium at finite temperature $T$ with a running coupling in temperature as described by the dynamical quasi-particles model). We use the perturbative elastic $(q(g) Q \rightarrow q (g) Q)$ cross section for the first case, and the Infrared Enhanced Hard Thermal Loop cross sections for the second. The results obtained in this work demonstrate the effects of a finite parton mass and width on the heavy quark transport properties and provide the basic ingredients for an explicit study of the microscopic dynamics of heavy flavors in the QGP - as formed in relativistic heavy-ion collisions - within transport approaches developed previously by the authors.