Phase diagram of QCD at finite temperature and chemical potential from lattice simulations with dynamical Wilson quarks

Abstract

We present the first results for lattice QCD at finite temperature $T$ and chemical potential $\ensuremath{\mu}$ with four flavors of Wilson quarks. The calculations are performed using the imaginary chemical potential method at $\ensuremath{\kappa}=0,0.001,0.15,0.165,0.17\text{ }\text{ }\mathrm{and}\text{ }\text{ }0.25$, where $\ensuremath{\kappa}$ is the hopping parameter, related to the bare quark mass $m$ and lattice spacing $a$ by $\ensuremath{\kappa}=1/(2ma+8)$. Such a method allows us to do large scale Monte Carlo simulations at imaginary chemical potential $\ensuremath{\mu}=i{\ensuremath{\mu}}_{I}$. By analytic continuation of the data with ${\ensuremath{\mu}}_{I}<\ensuremath{\pi}T/3$ to real values of the chemical potential, we expect at each $\ensuremath{\kappa}\ensuremath{\in}[0,{\ensuremath{\kappa}}_{\mathrm{chiral}}]$, a phase transition line on the $(\ensuremath{\mu},T)$ plane, in a region relevant to the search for quark-gluon plasma in heavy-ion collision experiments. The transition is first order at small or large quark mass, and becomes a crossover at intermediate quark mass.