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 by in-beam gamma-ray spectroscopic methods. The NORDBALL array equipped with a charged particle ball and 11 neutron detectors was used to detect the evaporated particles and gamma rays. The level schemes of Ga-6.5.67 were constructed 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, respectively. The structure of Ga-65.67 nuclei was described in the interacting boson-fermion plus broken pair modal, including quasiproton, quasiproton-two-quasineutron, and three-quasiproton fermion configurations in the boson-fermion basis states. Most of the states were: assigned to quasiparticle + phonon and their quasiparticle configurations on the basis of their electromagnetic decay properties, [S0556-2813(99)02004-X]. (Less)