Fluctuations and correlations in high temperature QCD

Abstract

We calculate second- and fourth-order cumulants of conserved charges in a temperature range stretching from the QCD transition region towards the realm of (resummed) perturbation theory. We perform lattice simulations with staggered quarks; the continuum extrapolation is based on ${N}_{t}=10--24$ in the crossover region and ${N}_{t}=8--16$ at higher temperatures. We find that the hadron resonance gas model predictions describe the lattice data rather well in the confined phase. At high temperatures (above $\ensuremath{\sim}250\text{ }\text{ }\mathrm{MeV}$) we find agreement with the three-loop hard thermal loop results.