Studies of the hybrid star structure within 2+1 flavors NJL model

Abstract: In this paper we use the equation of state (EOS) of 2+1 flavors Nambu-Jona-Lasinio (NJL) model to study the structure of compact stars. To avoid the ultraviolet divergence, we employ the proper-time regularization (PTR) with an ultraviolet cutoff. For comparison, we fix three sets of parameters, where the constraints of chemical equilibrium and electric charge neutrality conditions are taken into consideration. With a certain interpolation method in the crossover region, we construct three corresponding hybrid EOSs but find that the maximum masses of hybrid stars in the three different cases don't differ too much. It should be pointed out that, the results we get are in accordance with the recent astro-observation PSR J0348+0432, PSR J1614-2230, PSR J1946+3417.