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

TL;DR

This study uses lattice QCD simulations with physical quark masses to locate the critical point in the QCD phase diagram, finding it at T_E=162 MeV and =360 MeV, advancing understanding of QCD phase transitions.

Contribution

It provides the first lattice QCD determination of the QCD critical point with physical quark masses and larger volumes, improving previous estimates.

Findings

Critical point at T_E=162 b1 2 MeV and =360 b1 40 MeV.

Critical temperature at =0 is T_c=164 b1 2 MeV.

Decreased light quark masses to physical values affects the critical chemical potential.

Abstract

A critical point (E) is expected in QCD on the temperature (T) versus baryonic chemical potential (\mu) plane. Using a recently proposed lattice method for \mu \neq 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 \pm 2 MeV and \mu_E= 360 \pm 40 MeV. For the critical temperature at \mu=0 we obtained T_c=164 \pm 2 MeV. This work extends our previous study [Z. Fodor and S.D.Katz, JHEP 0203 (2002) 014] 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 \mu_E. Note, that the continuum extrapolation is still missing