Isospin symmetry breaking in atomic nuclei

TL;DR

This paper reviews the role of isospin symmetry breaking in atomic nuclei, emphasizing the need for ISB terms in models to accurately describe nuclear properties and analyzing their effects in different theoretical frameworks.

Contribution

It introduces explicit ISB terms into nuclear energy density functional and shell model approaches, providing detailed analysis of analogue states and isospin mixing effects.

Findings

Isospin mixing is largest for N=Z nuclei in the density functional approach.

ISB terms are essential to reproduce experimental isobaric analogue state data.

Explicit inclusion of ISB improves the understanding of nuclear structure properties.

Abstract

The importance of the isospin symmetry and its breaking in elucidating the properties of atomic nuclei is reviewed. The quark mass splitting and the electromagnetic origin of the isospin symmetry breaking (ISB) for nuclear many-body problem is discussed. The experimental data on isobaric analogue states cannot be described only with the Coulomb interaction, and ISB terms in the nucleon-nucleon interaction are needed to discern the observed properties. In the present work, the ISB terms are explicitly considered in nuclear energy density functional and spherical shell model approaches, and a detailed investigation of the analogue states and other properties of nuclei is performed. It is observed that isospin mixing is largest for the $N=Z$ system in the density functional approach.