Heavy Quark diffusion from lattice QCD spectral functions

TL;DR

This paper investigates charmonium spectral functions near the continuum limit on large lattices across different temperatures, providing evidence for a transport peak above the critical temperature and estimating the heavy quark diffusion constant.

Contribution

It presents the first lattice QCD analysis of the low frequency spectral functions near the continuum limit, highlighting the transport peak and estimating the diffusion constant.

Findings

Transport peak exists above T_c and is absent below T_c.

Heavy quark diffusion constant estimated using the Kubo formula.

Temperature dependence of charmonium spectral signatures analyzed.

Abstract

We analyze the low frequency part of charmonium spectral functions on large lattices close to the continuum limit in the temperature region $1.5\lesssim T/T_c\lesssim 3$ as well as for $T \simeq 0.75T_c$. We present evidence for the existence of a transport peak above $T_c$ and its absence below $T_c$. The heavy quark diffusion constant is then estimated using the Kubo formula. As part of the calculation we also determine the temperature dependence of the signature for the charmonium bound state in the spectral function and discuss the fate of charmonium states in the hot medium.