Recent shell-model calculations of gamma-decay strength functions

TL;DR

This paper presents recent shell-model calculations of gamma-decay strength functions in sd-pf and pf-shell nuclei, highlighting low-energy enhancements in M1 strength that impact neutron capture processes and exploring their relation to nuclear deformation.

Contribution

It provides new shell-model insights into gamma-decay strength functions, especially the low-energy M1 enhancement and its dependence on nuclear deformation.

Findings

Low-energy M1 strength enhancement observed in shell-model calculations.

Persistence of shell effects in the nuclear quasi-continuum.

Shape of the strength function linked to nuclear deformation.

Abstract

We present recent shell-model calculations of the gamma-decay in sd-pf and pf-shell nuclei. We focus on the M1 part of the dipole strength which was shown to exhibit interesting low-energy effects, in particular a low-energy enhancement which can have a considerable impact on the radiative neutron capture. We discuss the persistence of the shell effects in the nuclear quasi-continuum and the relation between the shape of the strength function at low energy and nuclear deformation.