Collective band structure in <SUP>66</SUP>Zn

The collective nature of states in 66Zn has been studied by carrying out a deformed configuration mixing shell model calculation in (1p3/20f5/21p1/20g9/2) model space. An effective interaction obtained for this space by Kuo has been used. The collective structure for 2 positive-parity bands and 5 negative-parity bands is identified. A qualitative understanding of the backbending at the J=6+ state in the yrast positive-parity band is given in terms of the band crossing of the ground-state band and the more deformed excited band arising from 2p2h excitation to the g9/2 orbit. Several high-spin members of the observed bands as well as in-band E2 transition strengths have been predicted