Comparison of the angular velocity and the angular momentum expansions for yrast band level energies in even-even nuclei

The results from the three- and the four-parameter expressions of the angular velocity expansion (AVE) and the angular momentum expansion (AME) are compared with the available experimental information on transition energies for yrast band levels in even-even nuclei. It is found that from the point of view of range of applicability, degree of fit to experimental transition energies, and high spin behavior, AME gives distinctly better results than AVE. The critical spin for backbending calculated from three-parameter AME is found to be in a fair agreement with the experimental data. NUCLEAR STRUCTURE Even-even rare earth nuclei, calculated yrast band transition energies, three- and four-parameter expansions in angular velocity and angular momentum, compared with experimental data.