CHIRAL PHASE TRANSITION IN HIGH TEMPERATURE QCD WITH MASSIVE QUARKS

The thermal phase transition in lattice QCD at finite quark mass is studied from the distribution of the zeros of the partition function in the complex quark mass plane. Results from simulations at strong and intermediate coupling are presented. Evidence for a chirally related transition at non-zero quark mass in the intermediate coupling region for β<5.2. The method exhibits remarkable stability in the evaluation of the critical mass as the lattice volume increases. Conclusions regarding the possible phase structure of QCD in the mass-temperature plane are discussed.