Collective Bands in the Neutron-Rich 110 Ru Nucleus

High spin states in neutron-rich Ru-110 nucleus have been investigated by measuring high-fold prompt gamma-ray coincidence events of the spontaneous fission of Cf-252 with the Gammasphere detector array. The ground-state band and the gamma-vibrational band have been confirmed and extended with spin up to 18h and 13h, respectively. The other three side bands, two proposed as two-quasiparticle bands and one proposed as a four-quasiparticle band, have been observed for the first time. The possible configurations for the quasi-particle bands are discussed. The cranked shell model calculations show that Ru-110 nucleus may have oblate triaxial deformation with parameters beta(2) = -0.30 and gamma = 24degrees, and the band crossing in the yrast band is due to the alignment of a pair of h(11/2) neutrons.