"Phase Diagram at Finite Temperature and Quark Density in the Strong Coupling Limit of Lattice QCD for Color SU(3)"

We study the phase diagram of quark matter at finite temperature (T) and chemical potential (μ) in the strong coupling limit of lattice QCD for color SU(3). We derive an analytical expression of the effective free energy as a function of T and μ, including baryon effects. The finite temperature effects are evaluated by integrating over the temporal link variable exactly in the Polyakov gauge with anti-periodic boundary condition for fermions. The obtained phase diagram shows the first and second order phase transition at low and high temperatures respectively and those are separated by the tri-critical point in the chiral limit. Baryon has effects to reduce the effective free energy and to extend the hadron phase to a larger mu direction at low temperatures.