Reconsideration of the 2-flavor NJL model with dimensional regularization at finite temperature and density

We study the 2-flavor Nambu--Jona-Lasinio (NJL) model at finite temperature, $T$, and chemical potential, $\mu$, in the dimensional regularization. The pion and sigma meson masses are calculated at finite $T$ and $\mu$. The color superconductivity is also discussed in the extended NJL model. We obtain the phase structure of the chiral and color symmetry in the dimensional regularization and compare the results with ones obtained in the cut-off regularization.