A fluid-dynamic approach to heavy-quark diffusion in the quark-gluon plasma

TL;DR

This paper develops a fluid-dynamic framework to describe heavy-quark diffusion in the quark-gluon plasma, providing insights into thermalization and transport properties relevant for understanding QGP behavior.

Contribution

It introduces a novel mapping of the Fokker-Planck equation to second-order fluid dynamics to analyze heavy-quark diffusion.

Findings

Fluid-dynamic description is feasible for charm quarks during late-stage QGP evolution.

Provides estimates for conductivities and relaxation times of heavy quarks.

Offers insights into the thermalization level of charm and bottom quarks in QGP.

Abstract

A fluid-dynamic approach to the diffusion of heavy quarks in the quark--gluon plasma (QGP) is presented. Specifically, we analyze the Fokker-Planck equation for the momentum transport of heavy quarks from a fluid perspective and use a mapping to second-order fluid-dynamics to determine conductivities and relaxation times governing their spatial diffusion. By investigating the relation between the two approaches, we provide new insights concerning the level of local thermalization of charm and bottom quarks inside the expanding QGP. Our results indicate that a fluid-dynamic description of diffusion is feasible for charm quarks at least for the latest stages of the fireball evolution.