Shell-model predictions for unique parity yrast configurations of odd-mass deformed nuclei

K. J. Weeks, Louisiana State University
J. P. Draayer, Louisiana State University


Features of a proposed shell-model coupling scheme for high-spin, unique parity states of odd-mass nuclei are investigated. Valence nucleons are assumed to be distributed among normal parity orbitals of a major shell and a unique parity intruder level. Basis states are built by weak coupling the leading configuration of each, the necessary further truncation being achieved by restricting the subspace configurations to leading representations of pseudo SU(3) for the normal parity space and quasispin for the unique parity part. The appearance of ΔI = 2 (stretched) and ΔI = 1 (ordered) band sequences is shown in lowest order to be a simple function of the number of particles in the unique parity orbital and their isospin and the background deformation provided by the normal parity part of the structure. Results of a simple model study which elucidates properties of the bands including energies, odd particle alignment, E2 and M1 rates and static moments are presented. Finally a survey of the experimental data that supports the model predictions is presented. © 1983.