Universal critical behavior and the transition temperature in (2+1)-flavor QCD

Abstract

We discuss the universal critical behavior in (2+1)‐flavor QCD by analyzing lattice data from improved staggered fermions generated by the HotQCD Collaboration. We present recent results from two different lattice discretizations and various lattice spacings (Nτ = 6,8,12) at fixed physical strange quark mass (ms) but varying light quark mass (ml). We find that the chiral order‐parameter, i.e. the chiral condensate, shows the expected universal scaling that is associated with the critical point in the chiral limit already for light quark masses ml/ms≲0.05. From an analysis of the disconnected chiral susceptibility we estimate a preliminary value of the QCD transition temperature.