Beta delayed neutron emission of $N=84$ $^{132}$Cd

TL;DR

This study combines experimental measurements and large-scale shell model calculations to analyze beta-delayed neutron emission in $^{132}$Cd, providing insights into nuclear decay processes relevant for astrophysics.

Contribution

The paper presents new experimental data on $^{132}$Cd decay and compares it with advanced shell model calculations, highlighting the limitations of existing global models.

Findings

Calculated half-lives and neutron branching ratios agree with known data.

Models overestimate half-lives of nuclei with $Z<50$ and $N extgreater=82$.

Shell model offers improved predictions for astrophysical nuclei.

Abstract

Using the time-of-flight technique, we measured the beta-delayed neutron emission of $^{132}$Cd. From our large-scale shell model (LSSM) calculation using the N$^3$LO interaction [Z.Y. Xu et al., Phys. Rev. Lett. 131, 022501 (2023)], we suggest the decay is dominated by the transformation of a neutron in the $g_{7/2}$ orbital, deep below the Fermi surface, into a proton in the $g_{9/2}$ orbital. We compare the beta-decay half-lives and neutron branching ratios of nuclei with $Z<50$ and $N\geq82$ obtained with our LSSM with those of leading "global" models such as Finite-Range Droplet Model (FRDM). Our calculations match known half-lives and neutron branching ratios well and suggest that current leading models overestimate the yet-to-be-measured half-lives. Our model, backed by the $^{132}$Cd decay data presented here, offers robust predictive power for nuclei of astrophysical interest such as $r$-process waiting points.