PUB - Publikationen an der Universität Bielefeld

The nonsinglet part of the chiral symmetry in quantum chromodynamics (QCD) with two light flavors is known to be restored through a crossover transition at a pseudocritical temperature. However, the temperature dependence of the singlet part of the chiral symmetry and whether it is effectively restored at the same temperature is not well understood. Using (2 + 1)-flavor QCD configurations generated using the M & ouml;bius domain-wall discretization on an N tau = 8 lattice, we construct suitable observables where the singlet and nonsinglet chiral symmetries are disentangled in order to study their temperature dependence across the crossover transition. From the peak of the disconnected part of the chiral susceptibility, we obtain a pseudocritical temperature Tpc = 158.7+2.6 -2.3 MeV where the nonsinglet part of the chiral symmetry is effectively restored. From a calculation of the topological susceptibility and its temperature dependence we find that the singlet UA(1) part of the chiral symmetry is not effectively restored at T less than or similar to 186 MeV.