$\chi_{\textrm{top}}(T \gg T_{\textrm{c}})$ in pure-glue QCD through reweighting

TL;DR

This paper computes the topological susceptibility in pure-glue QCD at high temperatures using a reweighting technique combined with gradient flow, improving statistical sampling of topological sectors.

Contribution

It introduces a reweighting method with gradient flow to effectively sample topological sectors at high temperatures in pure-glue QCD.

Findings

Topological susceptibility decreases at high temperatures.

Reweighting improves tunneling between topological sectors.

Method is viable for extension to full QCD with fermions.

Abstract

We calculate the topological susceptibility at 2.5 Tc and 4.1 Tc in SU(3) pure Yang-Mills theory. We define topology with the help of gradient flow and we largely overcome the problem of poor statistics at high temperatures by applying a reweighting technique in terms of the topological charge, measured after a specific small amount of gradient flow. This allows us to obtain a sample of configurations which compares topological sectors with good statistics, with enhanced tunneling between topologies. We quote continuum extrapolated results at these two temperatures and conclude that our method is viable and can be extended without new conceptual problems to the case of full QCD with fermions.