Octupole Deformation in Ba-144 and Ce-148

Gamma rays emitted by fission fragments of Cf-252 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 Ba-144 and Ce-148. In an even-A system, it is possible that rotational band structures are explainable by simplex quantum numbers, s = +1 and s = -1. In Ba-144 and Ce-148 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 Ba-144 and in Ce-148 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.