A chiral random matrix model with 2+1 flavors at finite temperature and density

Phase diagram of a chiral random matrix model with the degenerate ud quarks and the s quark at finite temperature and density is presented. The model exhibits a first-order transition at finite temperature for three massless flavors, owing to the U_A(1) breaking determinant term. We study the order of the transition with changing the quark masses and the quark chemical potential, and show that the first-order transition region expands as the chemical potential increases. We also discuss the behavior of the meson masses and the susceptibilities near the critical point.