Nucleon Superfluidity in Neutron Star Core with Direct URCA Cooling

Abstract

Nucleon superfluidity in a neutron star core with abundant protons making possible the direct URCA cooling is investigated using a realistic approach. It is found that the existence of both n- and p-superfluids is unlikely when the realistic effective mass of nucleons is taken into account. This leads to the conclusion that the direct URCA cooling would be excluded from the candidates of rapid cooling scenario of neutron stars and thereby constrain their masses.