Superfuidity in neutron-star matter

TL;DR

This paper investigates superfluidity in neutron-star matter using advanced nuclear interaction models, revealing that three-nucleon forces significantly reduce the superfluid energy gap at relevant densities.

Contribution

It introduces an improved CBF effective interaction incorporating three-nucleon forces to study superfluid gaps in neutron-star matter.

Findings

Superfluid transition occurs at neutron star inner crust densities.

Three-nucleon forces reduce the superfluid energy gap.

Results enhance understanding of neutron star interior properties.

Abstract

Correlated basis function perturbation theory and the formalism of cluster expansions have been recently employed to obtain an effective interaction from a state-of-the-art nuclear Hamiltonian. We report the results of a study of the superfluid gap in pure neutron matter, associated with formation of Cooper pairs in the $^1S_0$ sector. The calculations have been carried out using an improved version of the CBF effective interaction, in which three-nucleon forces are taken into account using a realistic microscopic model. Our results show that the superfluid transition occurs at densities corresponding to the neutron star inner crust, and that inclusion of three-nucleon interactions leads to a sizable reduction of the energy gap at the Fermi surface.