Shell-model description for the properties of the forbidden $\beta^-$ decay in the region "north-east" of $^{208}$Pb

TL;DR

This paper presents a detailed shell-model analysis of forbidden $eta^-$ decay properties in the region around $^{208}$Pb, including recent experimental data, half-lives, and Q-values, using a comprehensive computational approach.

Contribution

The study provides the first shell-model calculations for $eta^-$ decay transitions from the (8$^-$) isomeric state of $^{214}$Bi, expanding understanding of forbidden decays in this nuclear region.

Findings

Calculated $ ext{log ft}$ values match experimental data.

Predicted half-lives and Q-values for nuclei near $^{208}$Pb.

First shell-model results for specific forbidden decay transitions.

Abstract

In the present work, we report a comprehensive shell-model study of the $\log ft$ values for the forbidden $\beta^-$ decay transitions in the north-east region of $^{208}$Pb. For this we have considered $^{210-215}$Pb $\rightarrow$ $^{210-215}$Bi and $^{210-215}$Bi $\rightarrow$ $^{210-215}$Po transitions. We have performed shell-model calculation using KHPE interaction in valence shell 82-126 for protons and 126-184 for neutrons without any truncation. We have also calculated half-lives and Q-values for the concerned nuclei. Recently several $\log ft$ values are observed corresponding to $\beta^-$ decay from (8$^-$) isomeric state of $^{214}$Bi$^m$ at CERN-ISOLDE facility [Phys. Rev. C {\bf 104}, 054301 (2021)], and for the first time we have reported shell-model results for these transitions.