Octupole correlations in the actinides and the spdf-IBA model

The octupole bands in the Z similar to 88, N similar to 134 region, with th eir abundance of experimental information, offer a real challenge for diffe rent nuclear structure models. In this region, quasimolecular bands, which are thought to indicate the presence of stable octupole deformation, have b een observed. The quantities most often reported are the B(E1)/B(E2) branch ing ratios from these levels. The calculations in the framework of the spdf model show that the 1-pf boson limit (dipote-octupole vibrations) can desc ribe the essential experimental features related to the octupole bands in t he Rn-Th region. (C) 2001 MAIK "Nauka/Interperiodica".