Phase structure of lattice QCD with two flavors of Wilson quarks at finite temperature and chemical potential

Abstract

We present results for phase structure of lattice QCD with two degenerate flavors ($N_f=2$) of Wilson quarks at finite temperature $T$ and small baryon chemical potential $μ_B$. Using the imaginary chemical potential for which the fermion determinant is positive, we perform simulations at points where the ratios of pseudo-scalar meson mass to the vector meson mass $m_π/m_ρ$ are between $0.943(3)$ and $0.899(4)$ as well as in the quenched limit. By analytic continuation to real quark chemical potential $μ$, we obtain the transition temperature as a function of small $μ_B$. We attempt to determine the nature of transition at imaginary chemical potential by histogram, MC history, and finite size scaling. In the infinite heavy quark limit, the transition is of first order. At intermediate values of quark mass $m_q$ corresponding to the ratio of $m_π/m_ρ$ in the range from $0.943(3)$ to $0.899(4)$ at $aμ_I=0.24$, the MC simulations show absence of phase transition.