Thermalization of charm quarks in infinite and finite QGP matter

TL;DR

This paper investigates how charm quarks reach thermal equilibrium in quark-gluon plasma using Langevin dynamics, finding that thermalization times often exceed the plasma's lifetime, which impacts understanding of heavy quark behavior in high-energy collisions.

Contribution

It introduces a detailed analysis of charm quark thermalization using both static and hydrodynamic QGP models, highlighting the importance of diffusion constants.

Findings

Thermalization times are longer than QGP lifetime for typical diffusion constants.

Heavy quark diffusion is modeled via Langevin equations in dynamic and static media.

Results suggest limited thermalization of charm quarks within the QGP lifetime.

Abstract

We study the thermalization process of charm quarks in hot and dense matter. The diffusion of heavy quarks is calculated via a Langevin equation, both for a static medium as well as a QGP medium generated by a (3+1)D hydrodynamic model. We define two criteria for the thermalization of the heavy quarks, and observe thermalization times that are longer than the lifetime of the QGP phase for reasonable values of the diffusion constant.