Band terminations and maximum spin values with up to 18 aligned particles (and holes) in the to 82 shells
Abstract
Observed rotational bands that terminate or appear to terminate at very high spin are analyzed within the configuration constrained cranked Nilsson-Strutinsky (unpaired CNS or CNSB with pairing) formalism. Spin values for the nuclei discussed reach or come close to the maximum spin that can be built within the shells. Configurations are distinguished not only by the number of particles in high- and low- shells within each shell but, in some cases, also by the number of particles in pseudospin partners like and . Configurations in and , which terminate at , are well understood in terms of their occupation of open shells or groups of shells. The bands in are tentatively observed up to termination while the bands in are still a few spin units away. These terminating states are built with up to 18 aligned particles or 18 outside a core. The core is built from nucleons in filled shells, which gives no contribution to the spin. Analysis of the high-spin bands in and suggests that bands in and are observed to terminate at similar spin values, where terminating bands in are observed high above yrast. It is remarkable that the deformed mean field, plus single-particle configurations, is able to provide such a comprehensive description of known experimental levels in nuclei up to spin and beyond. It is also impressive that the model can relate alignments of single-particle spin vectors to changes in shape with the nuclear spin.