Weakly bound nuclei and realistic NN interactions

TL;DR

This paper develops a realistic low-momentum interaction model for weakly bound nuclei near the neutron drip line, successfully reproducing bulk properties and exploring the transition to neutron star crust matter.

Contribution

It introduces a combined interaction model based on $V_{lowk}$ and a density-dependent contact term, suitable for describing weakly bound nuclei and their transition to neutron star crusts.

Findings

Reproduces bulk properties of closed shell nuclei.

Effective for describing weakly bound nuclei.

Suitable for transition to neutron star crust matter.

Abstract

Nuclei close to the neutron drip line are described employing an interaction model which is based on the low-momentum interaction $V_{lowk}$. This effective two-body interaction which is determined to reproduce the nucleon-nucleon (NN) scattering data at energies below the pion thresh-hold is supplemented by a density-dependent contact interaction fitted to reproduce the saturation properties of infinite nuclear matter within the Hartree-Fock approach. It is demonstrated that corresponding calculations for closed shell-nuclei using this interaction model reproduce the bulk properties of these nuclei, independent whether the wave functions are expanded in terms of harmonic oscillator waves or in a basis of plane waves discretized in a spherical box of appropriate size. This plane wave basis, however, is more appropriate to describe weakly bound nuclei and the transition from discrete nuclei to homogeneous matter which is supposed to occur e.g. in the crust of neutron stars. Properties of exotic nuclei are studied within a Hartree-Fock plus BCS approximation.