Spin-Induced Interactions and Heavy-Quark Transport in the QGP

TL;DR

This paper enhances a T-matrix approach for the quark-gluon plasma by including spin-dependent interactions from relativistic corrections, leading to improved quarkonia spectroscopy and more accurate charm quark transport coefficients.

Contribution

It introduces a spin-dependent interaction model based on relativistic corrections to the Cornell potential, improving vacuum spectroscopy and in-medium potential constraints for heavy-quark transport.

Findings

Vector component in the confining potential improves quarkonia mass splittings.

Relativistic corrections increase charm quark thermal relaxation rates.

Enhanced transport coefficients impact heavy-flavor phenomenology at RHIC and LHC.

Abstract

A previously constructed $T$-matrix approach for studying the quark-gluon plasma (QGP) is improved by incorporating spin-dependent interactions between partons. These interactions arise from the relativistic corrections to the Cornell potential. We first study the vacuum spectroscopy of quarkonia with this potential and find that a significant admixture of a vector component in the confining potential (rather than the previously considered scalar interaction) improves the description of the experimental mass splittings in $S$- and $P$-wave states. The in-medium potential containing the vector component in the confining interaction is constrained by fitting lattice-QCD results for heavy-quark (HQ) free energies and the equation of state (EoS) computed within in the selfconsistent $T$-matrix framework. We subsequently extract the transport coefficients for charm quarks in the QGP with the improved in-medium potentials. The relativistic corrections to the vector component of the confining potential cause a notable increase in the thermal relaxation rate of charm quarks in the QGP in comparison to previous calculations, especially at high momenta. These results are expected to have significant ramifications for the phenomenology of open heavy-flavor observables at RHIC and the LHC.