Abstract: | Measurements of γ-ray yield functions, γ-γ coincidence spectra and y-ray angular distributions following the 64Ni(α, n) and (α, 2n) reactions have been made. Beam energies of 17 to 25 MeV were used. Among the new levels observed, with their proposed spin-parity assignments, are: in 66Zn, 3708 keV, (5)+; 3896 keV, 5?; 4812 keV, (7?); 5110 keV, (8?); 6417 keV; (10?); 7516 keV, (12+); and in 67Zn, 2937 keV, ; 3491 keV, or ; 3492 keV, ((si+)); 4221 keV, (?); 4631 keV, (); 4685 keV, (?). Comparison between the ground-state sequence, 0+ to 6+, in 66Zn and the first + to + levels in 67Zn strongly suggests that the latter be described as a g neutron orbital weakly coupled to the 66Zn core. Other sequences of high-spin 66Zn states are proposed to be formed from two-quasiparticle states containing the g excitation, coupled to the same ground-state sequence. |