Heavy quark diffusion coefficient with gradient flow
Nora Brambilla, Viljami Leino, Julian Mayer-Steudte, Péter Petreczky
Abstract
We calculate chromoelectric and chromomagnetic correlators in quenched QCD at $1.5{T}_{c}$ 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, ${\ensuremath{\kappa}}_{\mathrm{E}}$, as well as the coefficient of the first mass-suppressed correction, ${\ensuremath{\kappa}}_{\mathrm{B}}$. We use gradient flow for noise reduction. At $1.5{T}_{c}$ we obtain $1.70\ensuremath{\le}{\ensuremath{\kappa}}_{\mathrm{E}}/{T}^{3}\ensuremath{\le}3.12$ and $1.03<{\ensuremath{\kappa}}_{\mathrm{B}}/{T}^{3}<2.61$. The latter implies that the mass-suppressed effects in the heavy quark diffusion coefficient are 20% for bottom quarks and 34% for charm quarks at this temperature.