Velocity-induced Heavy Quarkonium Dissociation using the gauge-gravity correspondence

TL;DR

This paper uses gauge-gravity duality to study how heavy quarkonium states dissociate in a hot, strongly-coupled plasma, revealing velocity effects on potential screening and dissociation rates.

Contribution

It introduces a confining potential in the holographic model and analyzes velocity-dependent dissociation and thermal widths of quarkonium, extending previous perturbative and non-confining approaches.

Findings

Potential develops an imaginary part beyond a critical separation indicating dissociation.

Screening weakens with increased velocity due to effective temperature decrease.

Moving quarkonia have larger thermal widths, dissociating more easily than static ones.

Abstract

Using the gauge-gravity duality we have obtained the potential between a heavy quark and an antiquark pair, which is moving perpendicular to the direction of orientation, in a strongly-coupled supersymmetric hot plasma. For the purpose we work on a metric in the gravity side, {\em viz.} OKS-BH geometry, whose dual in the gauge theory side runs with the energy and hence proves to be a better background for thermal QCD. The potential obtained has confining term both in vacuum and in medium, in addition to the Coulomb term alone, usually reported in the literature. As the velocity of the pair is increased the screening of the potential gets weakened, which may be understood by the decrease of effective temperature with the increase of velocity. The crucial observation of our work is that beyond a critical separation of the heavy quark pair, the potential develops an imaginary part which is nowadays understood to be the main source of dissociation. The imaginary part is found to vanish at small $r$, thus agrees with the perturbative result. Finally we have estimated the thermal width for the ground and first excited states and found that non-zero rapidities lead to an increase of thermal width. This implies that the moving quarkonia dissociate easier than the static ones, which agrees with other calculations. However, the width in our case is larger than other calculations due to the presence of confining terms.