Semi-realistic nucleon-nucleon interactions with improved neutron-matter properties

TL;DR

This paper introduces new semi-realistic nucleon-nucleon interaction parameter-sets that better reproduce neutron-matter energies and nuclear properties, maintaining stability and shell structure predictions.

Contribution

The authors develop modified M3Y-based interactions that improve neutron-matter predictions while preserving finite nucleus properties and shell structure insights.

Findings

New parameter-sets M3Y-P6 and P7 show improved neutron-matter energy reproduction.

The interactions maintain stability of symmetric nuclear matter up to high densities.

Finite nucleus properties and shell effects are well described with the new parameters.

Abstract

New parameter-sets of the semi-realistic nucleon-nucleon interaction are developed, by modifying the M3Y interaction but maintaining the tensor channels and the longest-range central channels. The modification is made so as to reproduce microscopic results of neutron-matter energies, in addition to the measured binding energies of doubly magic nuclei including $^{100}$Sn and the even-odd mass differences of the Z=50 and N=82 nuclei in the self-consistent mean-field calculations. Separation energies of the proton- or neutron-magic nuclei are shown to be in fair agreement with the experimental data. With the new parameter-sets M3Y-P6 and P7, the isotropic spin-saturated symmetric nuclear matter remains stable in the density range as wide as $\rho\lesssim 6\rho_0$, while keeping desirable results of the previous parameter-set on finite nuclei. Isotope shifts of the Pb nuclei and tensor-force effects on shell structure are discussed.