$\beta$ and $\beta$-delayed neutron decay of the $N=82$ nucleus ${}_{49}^{131}$In${}_{82}$

Abstract

The half-lives of three $\beta$ decaying states of ${}_{49}^{131}$In${}_{82}$ have been measured with the GRIFFIN $\gamma$-ray spectrometer at the TRIUMF-ISAC facility to be $T_{1/2}(1/2^{-})=328(15)$~ms, $T_{1/2}(9/2^{+})=265(8)$~ms, and $T_{1/2}(21/2^{+})=323(55)$~ms, respectively. The first observation of $\gamma$-rays following the $\beta n$ decay of ${}^{131}$In into ${}^{130}$Sn is reported. The $\beta$-delayed neutron emission probability is determined to be $P_{1n}=12(7)\%$ for the $21/2^{+}$ state and $2.3(3)\%$ from the combined $1/2^{-}$ and $9/2^{+}$ states of ${}_{49}^{131}$In${}_{82}$ observed in this experiment. A significant expansion of the decay scheme of ${}^{131}$In, including 17 new excited states and 34 new $\gamma$-ray transitions in ${}_{50}^{131}$Sn${}_{81}$ is also reported. This leads to large changes in the deduced $\beta$ branching ratios to some of the low-lying states of ${}^{131}$Sn compared to previous work with implications for the strength of the first-forbidden $\beta$ transitions in the vicinity of doubly-magic ${}_{50}^{132}$Sn${}_{82}$.

14 pages, 15 figures, 5 tables

References in corpus (4)

• Neutron-gamma competition for $\beta$-delayed neutron emission
• Shell model half-lives for r-process N=82 nuclei
• The GRIFFIN Data Acquisition System
• Half-lives of neutron-rich ${}^{128-130}$Cd

Cited by in corpus (5)

• $\beta$ Decay of ${}^{132}$In and Spectroscopy of ${}^{132}$Sn and ${}^{131}$Sb with the GRIFFIN Spectrometer
• High-precision measurements of low-lying isomeric states in ${}^{120-124}$In with JYFLTRAP double Penning trap
• Gamow-Teller transitions of neutron-rich $N=82,81$ nuclei by shell-model calculations
• Neutron transfer reactions on the ground state and isomeric state of a 130Sn beam
• High-precision mass measurements of the ground and isomeric states in ${}^{124,125}$Ag