Prolate structures in Po-189 and Pb-185

The 3/2(-) isomer in Pb-185 and states above it have been populated in the α-decay of Po-189. The observed α-decay strengths to and the electromagnetic decay properties of the excited states in Pb-185 have been combined with Potential Energy Surface and Particle-Plus-Rotor calculations to propose configuration assignments. It is suggested that the α-decaying isomer of Po-189 is of prolate origin and that the prolate configuration becomes very low in energy in Pb-185.
QC 20100525