COLLECTIVE AND QUASI-PARTICLE EXCITATIONS IN CE-128

The level structure of the nucleus Ce-128 has been investigated via th e Rh-103(Si-28,p2n) reaction at a beam energy of 105 MeV. Six new band s have been found, Spin and parity of levels are assigned based on gam ma-ray angular distribution and angular correlation measurements. The properties of collective and quasiparticle excitations of Ce-128 are i nvestigated. A nu(h(11/2))(2) S-band is proposed and the crossing freq uency is found similar to that for Ba-126, The decoupled and semi-deco upled structures are discussed for the four negative-parity two-quasip roton bands. From an analysis of (g(K) - g(R))/Q(0) ratios, the nu h(1 1/2)(d(5/2), g(7/2)) configuration is proposed for a strongly coupled band structure.