COLLECTIVE EXCITED STATES IN EVEN–EVEN NUCLEI WITH QUADRUPOLE AND OCTUPOLE DEFORMATIONS

Abstract

Deformed even–even nuclei with quadrupole and octupole deformations are investigated on the basis of a nonadiabatical collective model. It is shown that the model satisfactorily describes energy levels of the yrast and first nonyrast bands with alternating parity in the rare-earth nuclei 150 Nd , 152, 154 Sm , 154 Gd , 156 Dy , 162, 164 Er and the actinides 232, 234, 236, 238 U . In the nuclei 156, 158 Gd , 224 Ra , 228 Th and 240 Pu the energy levels of second nonyrast bands are also described. The structure of the considered alternating-parity bands is examined in terms of odd–even staggering diagrams.