Abstract
Lifetimes were measured for the , , , , and levels in using a recently developed β-γ-γ fast timing method. In , the moment for the negative parity band was slightly larger than that for the positive parity band. The isovector E1 rates which were very small in and large in can be explained in terms of shell effects on the electric dipole moment. The new data are interpreted by both the spdf interacting boson and the reflection-asymmetric deformed shell models and provide compelling evidence for a static octupole deformation near .
- Received 19 December 1989
DOI:https://doi.org/10.1103/PhysRevC.41.R2469
©1990 American Physical Society