Spectroscopic studies of neutron-rich $^{129}$In and its $\beta$-decay daughter, $^{129}$Sn, using the GRIFFIN spectrometer

TL;DR

This study used the GRIFFIN spectrometer to analyze the beta decay of neutron-rich $^{129}$In, revealing new excited states in $^{129}$Sn and first observation of a specific isomeric decay with detailed level scheme updates.

Contribution

It provides new spectroscopic data on $^{129}$In and $^{129}$Sn, including 31 new gamma-ray transitions and the first observation of a particular isomeric decay.

Findings

Expanded the level scheme of $^{129}$Sn with 31 new gamma-ray transitions

First observation of the beta decay of the (29/2$^{+}$) 1911-keV isomeric state in $^{129}$In

Re-evaluated beta-branching ratios and level spin assignments

Abstract

The $\beta$-decay of neutron-rich $^{129}$In into $^{129}$Sn was studied using the GRIFFIN spectrometer at the ISAC facility at TRIUMF. The study observed the half-lives of the ground state and each of the $\beta$-decaying isomers. The level scheme of $^{129}$Sn has been expanded with thirty-one new $\gamma$-ray transitions and nine new excited levels, leading to a re-evaluation of the $\beta$-branching ratios and level spin assignments. The observation of the $\beta$-decay of the (29/2$^{+}$) 1911-keV isomeric state in $^{129}$In is reported for the first time, with a branching ratio of 2.0(5)$\%$.