The influence of antikaon condensations on nucleon 1S0 superfluidity in neutron star matter

Abstract The properties of neutron and proton 1S0 superfluidity are studied within the relativistic mean field and the Bardeen–Cooper–Schrieffer theories by taking the effects of K− and $\bar{K}^{0}$ condensations into account in neutron star matter without the hyperon degrees of freedom. It is found that antikaon condensations change the Fermi momenta, the effective masses and the single particle energies of nucleons in neutron star matter. These changes lead to a strong suppression of the neutron 1S0 superfluidity and an obvious enhancement of the proton 1S0 superfluidity in neutron star matter, respectively. In particular, the neutron and proton 1S0 pairing gaps are gradually shrinking with the optical potential of antikaons from −80 to −130 MeV. And antikaon condensations have little influence on the neutron 1S0 superfluid range, however, they have been markedly downsized the proton 1S0 superfluid range as the deepening of the optical potential of antikaons in neutron star matter. We also found that the nucleon 1S0 superfluidity and K− condensations within the scope of above optical potential of antikaons can occur in the core of PSR J1614-2230 and PSR J0348+0432 at the same time. Whereas $\bar{K}^{0}$ condensations only occur in the two pulsars when the range of optical potential of antikaons is from −100 to −130 MeV.