Heavy quark diffusion coefficient with gradient flow

TL;DR

This study estimates the heavy quark diffusion coefficient in quenched QCD at high temperatures using gradient flow, providing bounds on the electric and magnetic correlators and quantifying mass suppression effects.

Contribution

It introduces a method to calculate heavy quark diffusion coefficients at high temperatures using gradient flow in quenched QCD, including mass suppressed corrections.

Findings

Estimated bounds for $$ and $$ at $1.5T_c$

Mass suppression effects are 20% for bottom and 34% for charm quarks

Gradient flow effectively reduces noise in correlator calculations

Abstract

We calculate chromo-electric and chromo-magnetic correlators in quenched QCD at $1.5T_c$ and $10^4 T_c$ with the aim to estimate the heavy quark diffusion coefficient at leading order in the inverse heavy quark mass expansion, $\kappa_E$, as well as the coefficient of first mass suppressed correction, $\kappa_B$. We use gradient flow for noise reduction. At $1.5T_c$ we obtain: $1.70 \le \kappa_E/T^3 \le 3.12$ and $1.03< \kappa_B/T^3 < 2.61$. The latter implies that the mass suppressed effects in the heavy quark diffusion coefficient are 20% for bottom quarks and 34% for charm quark at this temperature.