A hybrid model of Skyrme- and Brueckner-type interactions for neutron star matter

Abstract

We suggest a hybrid model for neutron star matter to discuss the hyperon puzzle inherent in the 2.0 M-circle dot of the neutron star. For the nucleon-nucleon (NN) interaction, we employ the Skyrme-Hartree-Fock approach based on various Skyrme interaction parameter sets, and take the Brueckner-Hartree-Fock approach for the interactions related to hyperons. For the many-body interactions including hyperons, we make use of the multi-pomeron-exchange model, whose parameters have been adjusted to the data deduced from various hypernuclei properties. For clear understanding of the physics in the hybrid model, we discuss fractional functions of related particles, symmetry energies, and chemical potentials in dense matter. Finally, we investigate the equations of state and mass-radius relation of neutron stars, and show that the hybrid model can properly describe the 2.0 M-circle dot neutron star mass data with the many-body interaction employed in the hybrid model. Recent tidal deformability data from the gravitational wave observation are also compared to our calculations, especially in terms of the neutron skin of Pb-208 and nuclear incompressibility.