Octupole fragmentation and the structure of134Ba

Abstract

The low energy octupole states in {sup 134}Ba were examined using the inelastic scattering of 22 MeV protons. Strong fragmentation of the low energy octupole strength, which was observed in {sup 196,198}Pt and was identified as a signature of the O(6) dynamical symmetry limit of the interacting boson approximation (IBA), does {ital not} occur in {sup 134}Ba, which has been proposed to have O(6) structure. The model calculations demonstrate that there is, in fact, little difference in the structure of the low-lying positive parity levels between certain nuclei in a U(5){r_arrow}SU(3) (vibrator{r_arrow}rotor) transition and an O(6) nucleus ({gamma}-soft nucleus), but that the octupole fragmentation has an enhanced sensitivity to the d-boson composition of the wave functions and thereby reveals differences in structure that are not easily discernible with other observables. {copyright} {ital 1997} {ital The American Physical Society}