Study of chiral symmetry in lattice QCD at finite temperature and baryon density in the strong-coupling limit

We study chiral-symmetry breaking in lattice QCD at finite temperature (T) and at nonzero chemical potential (μ). Working at strong coupling in the Hamiltonian formalism with staggered fermions we analyzed the order of the chiral phase transition in the μ-T plane for one and two flavors. We found that ${\mu }_c$ (T=0) is independent of the number of flavors, while $T_c$ (μ=0) decreases when the number of flavors increases. We investigated the dependence of ${\mu }_c$ (T=0) on irrelevant terms added to the Hamiltonian.