Spin Alignment in Heavy Nuclei

Abstract

The Cranked Shell Model (CSM) interprets the rotational bands of deformed nuclei as configurations of quasiparticles moving in a rotating potential. The most important consequences of this independent particle picture, such as the additivity of the aligned angular momentum, the grouping of band crossings around characteristic frequencies and the oscillating strength of band mixing seem to be born out by the data on i13/2 neutron aligned bands. The alignment process in the other high spin orbitals, as h11/2-, h9/2-, i13/2-proton and j15/2-neutron are surveyed. The available data are compatible with the CSM-predictions. At the highest angular momenta high spin orbitals from the adjacent shells (specially i13/2-protons) enter the yrast region. An analysis of rotational bands in terms of aligned and collective angular momentum indicates a reduced collective part in the presence of aligned quasiparticles. The relation to γ-γ correlation experiments is discussed.