β decay of the very neutron-deficient Ge60 and Ge62 nuclei

Orrigo, S. E. A.; Rubio, B.; Gelletly, W.; Aguilera, P.; Algora, A.; Morales, A. I.; Agramunt, J.; Ahn, D. S.; Ascher, P.; Blank, B.; Borcea, C.; Boso, A.; Cakirli, R. B.; Chiba, J.; De Angelis, G.; De France, G.; Diel, F.; Doornenbal, P.; Fujita, Y.; Fukuda, N.; Ganioglu, E.; Gerbaux, M.; Giovinazzo, J.; Go, S.; Goigoux, T.; Grevy, S.; Guadilla, V.; Inabe, N.; Kiss, G. G.; Kubo, T.; Kubono, S.; Kurtukian-Nieto, T.; Lubos, D.; Magron, C.; Molina, F.; Montaner-Piza, A.; Napoli, D.; Nishimura, D.; Nishimura, S.; Oikawa, H.; Phong, V. H.; Sakurai, H.; Shimizu, Y.; Sidong, C.; Soderstrom, P. -A.; Sumikama, T.; Suzuki, H.; Takeda, H.; Takei, Y.; Tanaka, M.; Wu, J.; Yagi, S.

doi:10.1103/PhysRevC.103.014324

We report here the results of a study of the β decay of the proton-rich Ge isotopes, Ge60 and Ge62, produced in an experiment at the RIKEN Nishina Center. We have improved our knowledge of the half-lives of Ge62 [73.5(1) ms] and Ge60 [25.0(3) ms] and its daughter nucleus, Ga60 [69.4(2) ms]. We measured individual β-delayed proton and γ 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 β-delayed proton-emission branching ratio of 67(3)% has been obtained for Ge60. New information has been obtained on the energy levels populated in Ga60 and on the 1/2- excited state in the βp daughter Zn59. We extracted a ground state-to-ground state feeding of 85.3(3)% for the decay of Ge62. Eight new γ lines have been added to the deexcitation of levels populated in the Ga62 daughter.