Collective and broken pair states of 65,67Ga

Excited states of 65 Ga and 67 Ga nuclei were populated through the 12 C( 58 Ni,a p) and 12 C( 58 Ni,3p) reactions, respectively, and investigated by in-beam g-ray spectroscopic methods. The NORDBALL array equipped with a charged particle ball and 11 neutron detectors was used to detect the evaporated particles and g rays. The level schemes of 65,67 Ga were constructed on the basis of gg-coincidence relations up to 8.6 and 10 MeV excitation energy, and I p 527/2 and 33/2 1 spin and parity, respectively. The structure of 65,67 Ga nuclei was described in the interacting boson-fermion plus broken pair model, including quasiproton, quasiproton-two-quasineutron, and three-quasiproton fermion configurations in the boson-fermion basis states. Most of the states were assigned to quasiparticle 1 phonon and three quasiparticle configurations on the basis of their electromagnetic decay properties. @S0556-2813~99!02004-X#