Supersymmetry of identical bands in 171,172Yb supported by lifetime data

Precision lifetimes of six states in the ground-state bands of 171Yb have been measured using the recoil distance method following Coulomb excitation with a detector of the Euroball Cluster type at the FN-Tandem accelerator in Cologne. From these and previous data on branching and mixing ratios from Canberra, we found, that the transition quadrupole moments for corresponding E2 transitions in 171,172Yb are almost equal. This gives strong support for a weakly broken supersymmetry in 171,172Yb. On the other hand, the neighbor pair of nuclei 171Tm and 172Yb shows no supersymmetry demonstrating the importance of an even pseudoorbital angular momentum as condition for supersymmetry.