Reexamining Gamow-Teller decays near Ni 78

Decays of neutron-rich nuclei Zn82,83 and Ga82,83 produced in proton-induced fission of U238 were studied at the Holifield Radioactive Ion Beam Facility using on-line mass separation and β-γ spectroscopy techniques. New γ-ray transitions were identified and level schemes, which include states at high excitation energies in the range between 3-7 MeV were constructed. These high-energy levels were identified to be populated through allowed Gamow-Teller β transitions, and their structure was interpreted with new shell-model calculations. A β-delayed neutron branching ratio of 69±7% was deduced for Zn82 and revised β-decay half-life values of Zn82 [155(17)(20) ms] and Zn83 [122(28) ms] were determined