Particle-vibration coupling effect on the $\beta$-decay of magic nuclei

TL;DR

This paper studies how particle-vibration coupling affects the beta-decay of magic nuclei, showing it shifts Gamow-Teller strength and improves agreement with experimental half-lives, especially with the SkM* force.

Contribution

It introduces a particle-vibration coupling model on top of RPA calculations to better predict beta-decay properties of magic nuclei.

Findings

Gamow-Teller strength is shifted downward and fragmented.

Beta-decay half-lives are reduced, aligning better with experiments.

SkM* force reproduces both lifetimes and resonance line shapes.

Abstract

Nuclear $\beta$-decay in magic nuclei is investigated, taking into account the coupling between particle and collective vibrations,on top of self-consistent random phase approximation calculations based on Skyrme density functionals. The low-lying Gamow-Teller strength is shifted downwards and at times becomes fragmented; as a consequence, the $\beta$-decay half-lives are reduced due to the increase of the phase space available for the decay. In some cases, this leads to a very good agreement between theoretical and experimental lifetimes: this happens, in particular, in the case of the Skyrme force SkM*, that can also reproduce the line shape of the high energy Gamow-Teller resonance as it was previously shown.