Quarkonium in a QCD medium with momentum-dependent relaxation time

TL;DR

This paper investigates how incorporating momentum-dependent relaxation times in a kinetic theory framework affects the properties of quarkonia in a hot QCD medium, revealing significant differences from standard models.

Contribution

It introduces a novel kinetic theory approach with momentum-dependent relaxation times to study quarkonium properties in a QCD medium, improving the understanding of medium effects.

Findings

Significant variations in quarkonium binding energy with temperature.

Thermal width of quarkonia shows notable differences from standard models.

Highlighting the importance of microscopic collision timescales in quarkonium behavior.

Abstract

In this study, we explore the properties of quarkonia in a hot QCD medium using a newly proposed collision kernel that consistently incorporates the particle's momentum dependence into the relaxation time scale of the medium. The longitudinal component of the gluon self-energy, along with the Debye screening mass, is computed within the one-loop hard thermal loop framework by incorporating non-equilibrium corrections. A modified kinetic theory with an extended relaxation time approximation is employed to model the non-equilibrium dynamics of the QCD medium. The sensitivity of the heavy quarkonia potential to the momentum dependence of the relaxation time is studied. Further, we studied the binding energy and thermal width of quarkonia states within this new kinetic theory. Sizable variations in the temperature behavior of these quantities are observed in comparison with the standard relaxation time approximation method due to the particle momentum dependence on the relaxation timescale of the QCD medium. Our findings highlight that accounting for the microscopic nature of the collision timescale is crucial for understanding the quarkonium behavior in a QCD medium.