IDENTICAL BANDS - 2 STEPS FORWARD

The identical bands phenomenon has been studied in dl:tail both experi mentally and theoretically. A first step has been done by analysing th e distributions of the fractional change!; in the dynamical moments of inertia of superdeformed nuclei. They show that there is a clear exce ss of identical bands in superdeformed nuclei compared to normally-def ormed nuclei at low spin. Furthermore, this difference can be traced b ack to some special properties of superdeformed bands. The second step consists in the precise lifetime measurements that have been performe d in superdeformed nuclei of the rare earth region. The derived quadru pole moments support the picture that alignments and deformation effec ts cancel in identical bands.