Octupole Deformation in 144Ba and 148Ce
Gamma rays emitted by fission fragments of 252Cf and measured using the Gammasphere array continue to give insight into neutron rich nuclei. Using our high statistics data, we have reexamined high-spin states and linking transitions associated with octupole correlations in 144Ba and 148Ce. In an even-A system, it is possible that rotational band structures are explainable by simplex quantum numbers, s = +1 and s = -1. In 144Ba and 148Ce we have deduced spin values from angular correlations and assigned parities from mixing ratios for s = -1 characterized states. These are the first examples of both simplex bands in even-even nuclei. Extensions to higher spins of bands in 144Ba and in 148Ce are also reported. In addition to collective model analysis of energy displacement and rotational frequency, the intrinsic dipole moment via B(E2)/B(E1) ratios are also analyzed.
