Nuclear matter and neutron star properties calculated with a separable monopole interaction

Abstract

This paper presents a further application of a new model for the effective two-body nucleon-nucleon interaction using a density-dependent separable monopole (SMO) interaction. This model has recently been successfully used for calculating the ground-state properties of spherical, doubly closed-shell nuclei from ${}^{16}\mathrm{O}$ to ${}^{208}\mathrm{Pb}$ and is used here to calculate properties of infinite symmetric nuclear matter and the beta-stable $n+p+e+\ensuremath{\mu}$ matter of relevance for neutron stars. An equation of state (EOS) is constructed for this and is joined smoothly onto the Baym, Pethick, and Sutherland EOS for baryon number densities below $n=0.1{\mathrm{fm}}^{\ensuremath{-}3}$ and onto the widely used Bethe-Johnson EOS at $n=0.5{\mathrm{fm}}^{\ensuremath{-}3}.$ Nonrotating, zero-temperature neutron-star models have been calculated for this composite EOS and the results obtained are compared with those for models calculated with the Skyrme effective interaction and with realistic nucleon-nucleon potentials. The SMO interaction is shown to give excellent global agreement with a wide range of expected properties of infinite nuclear matter and of neutron stars.