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

摘要

Precision lifetimes of six states in the ground-state bands of Yb-171 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 front Canberra, we found, that the transition quadrupole moments for corresponding E2 transitions in Yb-171,Yb-172 are almost equal. This gives strong support for a weakly broken supersymmetry in Yb-171,Yb-172. On the other hand, the neighbor pair of nuclei Tm-171 and Yb-112 shows no supersymmetry demonstrating the importance of an even pseudoorbital angular momentum as condition for supersymmetry. (C) 2002 Published by Elsevier Science B.V. [References: 35]