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

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