Beta decay of the very neutron-deficient $^{60}$Ge and $^{62}$Ge nuclei

TL;DR

This study investigates the beta decay of neutron-deficient $^{60}$Ge and $^{62}$Ge isotopes, providing improved half-lives, decay schemes, transition strengths, and new gamma lines, enhancing understanding of their nuclear structure.

Contribution

The paper presents new measurements of half-lives, decay modes, and gamma emissions for $^{60}$Ge and $^{62}$Ge, offering detailed decay schemes and transition data not previously available.

Findings

Half-lives of $^{60}$Ge and $^{62}$Ge determined.

Decay schemes and transition strengths established.

Eight new gamma lines identified in $^{62}$Ga de-excitation.

Abstract

We report here the results of a study of the $\beta$ decay of the proton-rich Ge isotopes, $^{60}$Ge and $^{62}$Ge, produced in an experiment at the RIKEN Nishina Center. We have improved our knowledge of the half-lives of $^{62}$Ge (73.5(1) ms), $^{60}$Ge (25.0(3) ms) and its daughter nucleus, $^{60}$Ga (69.4(2) ms). We measured individual $\beta$-delayed proton and $\gamma$ emissions and their related branching ratios. Decay schemes and absolute Fermi and Gamow-Teller transition strengths have been determined. The mass excesses of the nuclei under study have been deduced. A total $\beta$-delayed proton-emission branching ratio of 67(3)% has been obtained for $^{60}$Ge. New information has been obtained on the energy levels populated in $^{60}$Ga and on the 1/2$^-$ excited state in the $\beta p$ daughter $^{59}$Zn. We extracted a ground state to ground state feeding of 85.3(3)% for the decay of $^{62}$Ge. Eight new $\gamma$ lines have been added to the de-excitation of levels populated in the $^{62}$Ga daughter.