A microscopic model beyond mean-field: from giant resonances properties to the fit of new effective interactions

TL;DR

This paper develops a microscopic beyond mean-field model for nuclear systems, addressing limitations of mean-field approaches by incorporating collective and single-particle properties, and proposes steps for refitting Skyrme interactions with these effects.

Contribution

It introduces a microscopic beyond mean-field framework for nuclear models and discusses refitting Skyrme interactions to include beyond mean-field effects.

Findings

Addressed limitations of mean-field models in nuclear physics.

Outlined steps for refitting Skyrme interactions with beyond mean-field contributions.

Discussed divergence issues with zero-range interactions in this context.

Abstract

A completely microscopic beyond mean-field approach has been elaborated to overcome some intrinsic limitations of self-consistent mean-field schemes applied to nuclear systems, such as the incapability to produce some properties of single-particle states (e.g. spectroscopic factors), as well as of collective states (e.g. their damping width and their gamma decay to the ground state or to low lying states). Since commonly used effective interactions are fitted at the mean-field level, one should aim at refitting them including the desired beyond mean-field contributions in the refitting procedure. If zero-range interactions are used, divergences arise. We present some steps towards the refitting of Skyrme interactions, for its application in finite nuclei.