A non-perturbative estimate of the heavy quark momentum diffusion coefficient

TL;DR

This paper provides a non-perturbative estimate of the heavy quark momentum diffusion coefficient in a pure SU(3) plasma at high temperature, using lattice QCD simulations and spectral function modeling.

Contribution

It introduces a continuum extrapolation of the colour-electric correlator and estimates the transport coefficient with systematic uncertainties, advancing understanding of heavy quark dynamics in quark-gluon plasma.

Findings

Estimated kappa = (1.8 - 3.4)T^3 for heavy quarks.

Derived drag coefficient range of (1.8 - 3.4) (Tc/T)^2 (M/1.5GeV) fm/c.

Results applicable to bottom and charm quarks with systematic uncertainties.

Abstract

We estimate the momentum diffusion coefficient of a heavy quark within a pure SU(3) plasma at a temperature of about 1.5Tc. Large-scale Monte Carlo simulations on a series of lattices extending up to 192^3*48 permit us to carry out a continuum extrapolation of the so-called colour-electric imaginary-time correlator. The extrapolated correlator is analyzed with the help of theoretically motivated models for the corresponding spectral function. Evidence for a non-zero transport coefficient is found and, incorporating systematic uncertainties reflecting model assumptions, we obtain kappa = (1.8 - 3.4)T^3. This implies that the "drag coefficient", characterizing the time scale at which heavy quarks adjust to hydrodynamic flow, is (1.8 - 3.4) (Tc/T)^2 (M/1.5GeV) fm/c, where M is the heavy quark kinetic mass. The results apply to bottom and, with somewhat larger systematic uncertainties, to charm quarks.