Quarkonium dissociation in the presence of a small momentum space anisotropy

TL;DR

This paper investigates how small momentum space anisotropy affects heavy quarkonium dissociation temperatures in near-equilibrium media, revealing that entropy considerations influence the dissociation threshold.

Contribution

It provides a first-order analysis of quarkonium dissociation in anisotropic media, highlighting the role of entropy density differences.

Findings

Dissociation temperature remains unchanged for isentropic anisotropic media.

In non-equilibrium states with lower entropy density, dissociation temperature increases by up to 10%.

The study offers insights into quarkonium behavior in anisotropic quark-gluon plasma.

Abstract

We consider the dissociation of heavy quarkonium in a medium close to thermal equilibrium but with a small momentum space anisotropy. Dissociation is defined to take place when the width of the ground state equals its binding energy. We show that if the anisotropic medium is obtained isentropically from the equilibrium one, then to first order in the anisotropy parameter the dissociation temperature remains unchanged. If, in contrast, the non-equilibrium system has a smaller entropy density than the equilibrium one, then the dissociation temperature increases with respect to the isotropic case, by up to 10% for modest anisotropies.