The thermal width of heavy quarkonia moving in quark gluon plasma

TL;DR

This paper calculates how the thermal width of moving heavy quarkonia in quark-gluon plasma depends on velocity, revealing contrasting behaviors at leading and next-to-leading order in perturbative QCD.

Contribution

It provides the first NLO calculation of the velocity dependence of heavy quarkonia thermal width in QGP, showing an increasing trend at NLO unlike the decreasing LO trend.

Findings

At LO, the width decreases with velocity.

At NLO, the width increases with velocity.

NLO dissociation cross section approaches a constant at high energy.

Abstract

The velocity dependence of the thermal width of heavy quarkonia traveling with respect to the quark gluon plasma is calculated up to the NLO in perturbative QCD. At the LO, the width decreases with increasing speed, whereas at the NLO it increases with a magnitude approximately proportional to the expectation value of the relative velocity between the quarkonium and a parton in thermal equilibrium. Such an asymptotic behavior is due to the NLO dissociation cross section converging to a nonvanishing value in the high energy limit.