Topological susceptibility from $N_f=2+1+1$ lattice QCD at nonzero temperature

Understand

We present results for the topological susceptibility at nonzero temperature obtained from lattice QCD with four dynamical quark flavours.

• We apply different smoothing methods, including gradient Wilson flow and over--improved cooling, before calculating the susceptibility.
• It is shown that the considered smoothing techniques basically agree among each other, and that there are simple scaling relations between flow time and the number of cooling/smearing steps.
• The topological susceptibility exhibits a surprisingly slow decrease at high temperature.