A new effective interaction for $0\hbar\omega$ shell model calculations in the sdpf valence space

TL;DR

This paper introduces SDPF-U, an improved effective interaction for shell model calculations in the sdpf valence space, enhancing accuracy for neutron-rich isotopes near N=28.

Contribution

The paper develops SDPF-U, a modified interaction combining USD and KB3G, extending applicability and reliability over previous models for sdpf shell calculations.

Findings

SDPF-U better reproduces experimental data for neutron-rich isotopes.

The interaction explains the disappearance of N=28 shell closure for Z<=16.

Enhanced predictive power for sdpf shell model calculations.

Abstract

The neutron rich isotopes with Z<20, in particular those with neutron numbers around N=28,have been at the focus of a lot experimental and theoretical scrutiny during the last few years.Shell model calculations using the effective interaction SDPF-NR, were able to predictor to explain most of the properties featured by these nuclei. Prominent among them is the disappearance of the N=28 shell closure for Z<=16. We have incorporated to SDPF-NR some modifications, either on purely theoretical grounds or guided by new experimental information. The proposed interaction, SDPF-U, contains USD as its sd-shell part and KB3G as its pf-shell-part. Its range of applicability is enlarged and its reliability enhanced with respect to the earlier version.