Critical point of QCD at finite T and μ, lattice results for physical quark masses

A critical point (E) is expected in QCD on the temperature (T) versus baryonic chemical potential (μ) plane. Using a recently proposed lattice method for μ ≠ 0 we study dynamical QCD with n_f = 2+1 staggered quarks of physical masses on L_t = 4 lattices. Our result for the critical point is T_E = 162 ± 2MeV and μ_E = 360 ± 40MeV. For the critical temperature at μ = 0 we obtained T _c = 164 ± 2 MeV. This work extends our previous study [8] by two means. It decreases the light quark masses (m_u,d) by a factor of three down to their physical values. Furthermore, in order to approach the thermodynamical limit we increase our largest volume by a factor of three. As expected, decreasing m_u,d decreased μ_E. Note, that the continuum extrapolation is still missing. Institute for Theoretical Physics, Eötvös University, Hungary.