Heavy quark correlations and the effective volume for quarkonia production

TL;DR

This paper investigates the effective volume of correlated heavy quark pairs in a quark-gluon plasma using Boltzmann transport, revealing its dependence on momentum, temperature, and time, and showing the pairs attain a thermal-like temperature.

Contribution

It introduces a detailed analysis of the effective volume of heavy quark pairs in a medium, highlighting its dynamic behavior and thermalization properties.

Findings

Effective volume depends on quark momentum and medium temperature.

Effective volume initially grows linearly with time, then slower, finally as t^{3/2}.

Heavy quark pairs attain a temperature similar to the medium despite non-thermal initial spectra.

Abstract

Using the Boltzmann transport approach, we study the effective volume of a correlated heavy quark pair in a partonic medium based on their collision rate. We find that the effective volume is finite and depends sensitively on the momentum of the heavy quark and the temperature of the medium. Generally, it increases linearly with time $t$ at the very beginning and the increase then becomes slower due to multiple scattering, and finally it increases linearly with respect to $t^{3/2}$. We further find that the colliding heavy quark pair has an effective temperature similar to that of the medium even though their initial transverse momentum spectra are far from thermal equilibrium.