QCD phase diagram with 2-flavor lattice fermion formulations

We propose a new framework for investigating two-flavor lattice QCD with finite temperature and density by applying the Karsten-Wilczek lattice fermion, in which a species-dependent imaginary chemical potential can reduce the number of species to two without losing chiral symmetry. This lattice discretization is useful for study on finite-(T;m) QCD since its discrete symmetries are appropriate for the case. To show its applicability, we study strong-coupling lattice QCD with temperature and chemical potential. We derive the effective potential of the scalar meson field and obtain a critical line of the chiral phase transition, which is qualitatively consistent with the phenomenologically expected phase diagram.