A T-Matrix Calculation for in-Medium Heavy-Quark Gluon Scattering

TL;DR

This paper develops a T-matrix approach to study heavy-quark interactions with gluons in the Quark-Gluon Plasma, incorporating lattice-QCD motivated potentials and corrections, leading to enhanced scattering predictions.

Contribution

It introduces a comprehensive T-matrix calculation for in-medium heavy-quark gluon scattering, including corrections and lattice-QCD inputs, providing improved scattering amplitudes and transport coefficients.

Findings

Enhanced HQ drag coefficient by a factor of 2-3 over perturbative results.

Inclusion of lattice-QCD motivated potentials and corrections.

Resummation effects significantly increase attractive channel interactions.

Abstract

The interactions of charm and bottom quarks in a Quark-Gluon Plasma (QGP) are evaluated using a thermodynamic 2-body T-matrix. We specifically focus on heavy-quark (HQ) interactions with thermal gluons with an input potential motivated by lattice-QCD computations of the HQ free energy. The latter is implemented into a field-theoretic ansatz for color-Coulomb and (remnants of) confining interactions. This, in particular, enables to discuss corrections to the potential approach, specifically hard-thermal-loop corrections to the vertices, relativistic corrections deduced from pertinent Feynman diagrams, and a suitable projection on transverse thermal gluons. The resulting potentials are applied to compute scattering amplitudes in different color channels and utilized for a calculation of the corresponding HQ drag coefficient in the QGP. A factor of ~2-3 enhancement over perturbative results is obtained, mainly driven by the resummation in the attractive color-channels.