Effects of tensor couplings of ω and ρ mesons on 1S0 nucleon superfluidity in neutron star matter

The [Formula: see text] nucleon superfluidity in neutron star matter was investigated in the framework of relativistic [Formula: see text] model with the tensor couplings of [Formula: see text] and [Formula: see text] mesons using the relativistic Hartree–Fock (RHF) approximation. It was found that the tensor couplings of [Formula: see text] and [Formula: see text] mesons lead to a clear growth of the [Formula: see text] neutron pairing gap in the density range where there exists [Formula: see text] neutron superfluidity. The [Formula: see text] pairing gap of proton with the tensor couplings of [Formula: see text] and [Formula: see text] mesons in the density range of [Formula: see text]–[Formula: see text][Formula: see text]fm[Formula: see text] is lower and then in the density range of [Formula: see text]–[Formula: see text][Formula: see text]fm[Formula: see text] higher than the corresponding value without the tensor couplings of [Formula: see text] and [Formula: see text] mesons. Our results provide a basic to understand the influence of the tensor couplings of [Formula: see text] and [Formula: see text] mesons on the cooling properties of neutron star.

QUASI TWO-DIMENSIONAL NUCLEON SUPERFLUIDITY UNDER LOCALIZATION WITH PION CONDENSATION

The aim here is to show an example for localization and relevant low-dimensional superfluids in nuclear system. Due to a particular property of tensor force originating from the One-Pion-Exchange (OPE) between two nucleons, dense nuclear medium undergoes a layer confinement of the nucleons on one hand and also pion condensation (PC) for pion field mediating two-nucleon interaction on the other hand. The localization is characterized by a layered structure with a specific spin-isospin ordering. In that situation, the pairing problem has a two-dimensional (2D) character, i.e., low-dimensional superfluid realized in the hadronic matter with strong interactions. The pairing description suitable to the 2D nature is presented and possible realization of superfluidity in neutron stars is discussed, togeter with its effect on the cooling scenarios.

EQUATION OF STATE AND SINGLE-PARTICLE PROPERTIES OF NEUTRON-RICH NUCLEAR MATTER

We report our research work on the equation of state (EOS) and single-particle (s.p.) properties of neutron-rich nuclear matter within the framework of the Brueckner–Bethe–Goldstone approach extended to include a microscopic three-body force (TBF). We show that inclusion of the TBF provide a largely improvement of the predicted nuclear matter saturation properties and leads to a strongly stiffening of the density dependence of symmetry energy at high densities. The neutron effective mass turns out to be greater than the proton one in neutron-rich nuclear matter in both cases of including and not including the TBF. The TBF induces a strongly repulsive rearrangement contribution to nucleon s.p. potential at high densities and large momenta. The TBF rearrangement contribution reduces considerably the attraction of the neutron and proton s.p. potentials and enhances strongly their momentum-dependence at high densities and high momenta. The TBF effect on nucleon superfluidity in neutron star matter has also been discussed.