PUB - Publikationen an der Universität Bielefeld

We present a lattice QCD based determination of the chiral phase transition temperature in QCD with two massless (up and down) and one strange quark having its physical mass. We propose and calculate two novel estimators for the chiral transition temperature for several values of the light quark masses, corresponding to Goldstone pion masses in the range of 58 MeV≲mπ≲163 MeV58~{\rm MeV}\lesssim m_\pi\lesssim 163~{\rm MeV}58 MeV≲mπ​≲163 MeV. The chiral phase transition temperature is determined by extrapolating to vanishing pion mass using universal scaling relations. After thermodynamic, continuum and chiral extrapolations we find the chiral phase transition temperature Tc0=132−6+3T_c^0=132^{+3}_{-6}Tc0​=132−6+3​ MeV. We also show some preliminary calculations that use the conventional estimator for the pseudo-critical temperature and compare with the new estimators for Tc0T_c^0Tc0​. Furthermore, we show results for the ratio of the chiral order parameter and its susceptibility and argue that this ratio can be used to differentiate between O(N)O(N)O(N) and Z2Z_2Z2​ universality classes in a non-parametric manner.