The role of three-nucleon potentials within the shell model: past and present

TL;DR

This paper reviews the influence of three-nucleon forces on nuclear shell structure, emphasizing recent advances from chiral perturbation theory that enable more accurate microscopic modeling of nuclei.

Contribution

It provides an update on shell model calculations using chiral three-nucleon potentials, highlighting their impact on understanding shell evolution and nuclear properties.

Findings

Three-nucleon forces are essential for accurate shell evolution modeling.

Chiral potentials improve agreement with experimental data.

Inclusion of three-body forces affects driplines and shell closures.

Abstract

We survey the impact of nuclear three-body forces on structure properties of nuclei within the shell model. It has long been acknowledged, since the seminal works of Zuker and coworkers, that three-body forces play a fundamental role in making the monopole component of shell-model Hamiltonians, derived from realistic nucleon-nucleon potentials, able to reproduce the observed evolution of the shell structure. In the vast majority of calculations, however, their effects have been taken into account by shell-model practitioners by introducing ad hoc modifications of the monopole matrix elements. During last twenty years, a new theoretical approach, framed within the chiral perturbation theory, has progressed in developing nuclear potentials, where two- and many-body components are naturally and consistently built in. This new class of nuclear forces allows to carry out nuclear structure studies that are improving our ability to understand nuclear phenomena in a microscopic approach. We provide in this work an update on the status of the nuclear shell model based on realistic Hamiltonians that are derived from two- and three-nucleon chiral potentials, focusing on the role of the three-body component to provide the observed shell evolution and closure properties, as well as the location of driplines. To this end, we present the results of shell-model calculations and their comparison with recent experimental measurements, which enlighten the relevance of the inclusion of three-nucleon forces to master our knowledge of the physics of atomic nuclei.