Non-yrast states of 134Ce populated in beta-decay

Non-yrast low spin states of the nucleus 134Ce were studied by means of gamma-spectroscopy following the beta-decay of 134Pr. The activity was produced with the reaction 117Sn(19F, 4n)13Pr at the Cologne FN TANDEM accelerator in the center of the OSIRIS-cube spectrometer. The beta-decay of the ground and medium spin isomeric states in 134Pr populates states with spins up to 8h and excitation energies up to 4.1 MeV in 134Ce. Besides ground and quasi-gamma bands, an excited band based on the 02+-state ("K = 0"-band), the "K = 4"-band and many other low lying states were observed. The gamma gamma angular correlations were analyzed to assign spins and parities to the excited states, and to determine the multipolarities of the gamma-transitions. We found dominant E2-transitions in the quasigamma band and from the gamma to the ground band. The experimental data are compared with calculations using the Interacting Boson Model (IBM). Good agreement is reached in the vicinity of the 0(6)-limit.