$\beta$ Decay of $^{132}$In and Spectroscopy of $^{132}$Sn and $^{131}$Sb with the GRIFFIN Spectrometer

TL;DR

This study used the GRIFFIN spectrometer to perform detailed spectroscopy of $^{132}$Sn and $^{131}$Sb following the $eta$ decay of $^{132}$In, determining excited states, transition placements, and the $eta$-delayed neutron emission probability.

Contribution

It provides the first measurement of the $eta$-delayed neutron emission probability for $^{132}$In using $eta$-delayed $ ext{gamma}$ spectroscopy and compares experimental results with novel ab initio calculations.

Findings

70 transitions and 29 excited states in $^{132}$Sn identified.

$P_{n}$ for $^{132}$In measured as 12.3(4)% using $ ext{gamma}$ spectroscopy.

$ ext{gamma}$-$ ext{gamma}$ angular correlations support spin assignments.

Abstract

Spectroscopy of doubly magic $^{132}_{50}$Sn$_{82}$ has been performed with the GRIFFIN spectrometer at TRIUMF-ISAC following the $\beta$ decay of $^{132}_{49}$In$_{83}$. The analysis has allowed for the placement of a total of 70 transitions and 29 excited states in $^{132}$Sn. Detailed spectroscopy has also been performed on $^{131}$Sb, resulting from the $\beta$ decay of $^{131}$Sn, produced from the $\beta$-delayed neutron decay of $^{132}$In. Measurement of $\gamma$-rays in both $^{131}$Sn and $^{131}$Sb has led to the determination of the $\beta$-delayed neutron emission probability, $P_{n}$, from $^{132}$In. This is the first time the $P_{n}$ has been measured for this nucleus using $\gamma$ spectroscopy, and the new value of 12.3(4)% is consistent with the most recent $\beta-n$ counting experiment. Additionally, $\gamma$-$\gamma$ angular correlations have been performed in $^{132}$Sn, supporting the spin assignments of several excited states. Novel ab initio calculations are presented which describe several of the excited states, and these are compared to the experimental spectrum.