Collective and broken pair states of Ga-65,Ga-67

Excited states of Ga-65 and Ga-67 nuclei were populated through the C-12(Ni -58,alpha p) and C-12(Ni-58,3p) reactions, respectively, and investigated b y in-beam gamma-ray spectroscopic methods. The NORDBALL array equipped with a charged particle ball and 11 neutron detectors was used to detect the ev aporated particles and gamma rays. The level schemes of Ga-6.5.67 were cons tructed On the basis of gamma gamma-coincidence relations up to 8.6 and 10, MeV excitation energy, and I-pi=27/2 and 33/2(+) spin and parity, respectiv ely. The structure of Ga-65.67 nuclei was described in the interacting boso n-fermion plus broken pair modal, including quasiproton, quasiproton-two-qu asineutron, and three-quasiproton fermion configurations in the boson-fermi on basis states. Most of the states were: assigned to quasiparticle + phono n and their quasiparticle configurations on the basis of their electromagne tic decay properties, [S0556-2813(99)02004-X].