β decay of the very neutron-deficient 60Ge and 62Ge nuclei

We report here the results of a study of the beta decay of the proton-rich Ge isotopes, Ge-60 and Ge-62, produced in an experiment at the RIKEN Nishina Center. We have improved our knowledge of the half-lives of Ge-62 [73.5(1) ms] and Ge-60 [25.0(3) ms] and its daughter nucleus, Ga-60 [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 Ge-60. New information has been obtained on the energy levels populated in Ga-60 and on the 1/2(-) excited state in the beta p daughter Zn-59. We extracted a ground state-to-ground state feeding of 85.3(3)% for the decay of Ge-62. Eight new y lines have been added to the deexcitation of levels populated in the Ga-62 daughter.

Automated summary

In this study, the beta decay of the proton-rich Ge isotopes, Ge-60 and Ge-62, was investigated, revealing detailed information on their half-lives, beta-delayed proton and gamma emissions, branching ratios, decay schemes, and transition strengths. New data on the energy levels of Ga-60 and the excited state in the Zn-59 daughter nucleus were obtained, along with insights into the mass excesses of the nuclei under study. The results also include the determination of the branching ratios and feeding probabilities for the decay processes studied.