Quasi-Neutron 3P2-Dominant Superfluidity under ;0 Condensation with Isobar

Abstract

To seek the possibility of baryonic superfluidity persisting at high density in neutron stars, the 3P2-dominant superfluidity under developed neutral-pion (π0) condensation, i.e., the coexistence of two hadronic condensates, is investigated by taking into account the Δ; isobar degrees of freedom. The problem is formulated as the 3P2-dominant pairing of the quasi-neutrons, described by a superposition of the neutron and the Δ0, in the alternating-layer-spin (ALS) structure equivalent to the π0 condensation. Formulation given in previous papers is extended to thatexplicitly including Δ-mixing on the basis of the SU(4) quark model. Effects of Δ-mixing to the pairing potential are expressed in a compact form as a modification of the spin-isospin terms of nuclear forces. We find the possibility that the coexistence is likely up to the density region higher than 6ρ0 (ρ;0 being the nuclear density) in neutron star interior, with the superfluid critical temperature much higher than the internal temperature of neutron stars, if a type of nuclear forces with a gentle odd-state core is adopted. The conclusion depends on the features of the spin-isospin terms of nuclear forces enhanced by Δ-mixing, especially at short distances. for a type of nuclear forces with a steep odd-state core, the existence of the superfluid is limited to the density region less than about 4ρ0. Discussion is given concerning the dependence of the results on the interaction, the parameters of the ALS structure, effective mass and so forth.