Singlet Pairing Gaps of Neutrons and Protons in Hyperonic Neutron stars

The 1 S 0 nucleonic superfluids are investigated within the relativistic mean-field model and Bardeen-Cooper-Schrieffer theory in hyperonic neutron stars. The 1 S 0 pairing gaps of neutrons and protons are calculated based on the Reid soft-core interaction as the nucleon-nucleon interaction. In particular, we have studied the influence of degrees of freedom for hyperons on the 1 S 0 nucleonic pairing gap in neutron star matter. It is found that the appearance of hyperons has little impact on the baryonic density range and the size of the 1 S 0 neutronic pairing gap; the 1 S 0 protonic pairing gap also decreases slightly in this region where ρ B = 0.0–0.393 fm −3 . However, if baryonic density becomes greater than 0.393 fm −3 , the 1 S 0 protonic pairing gap obviously increases. In addition, the possible range for a protonic superfluid is obviously enlarged due to the presence of hyperons. In our results, the hyperons change the 1 S 0 protonic pairing gap, which must change the cooling properties of neutron stars.