Correlation Studies of Rotational Behavior at Very High Angular Momentum

Abstract

Transition-energy correlations are studied in rotational erbium nuclei up to 1250 keV. A collective moment of inertia ${\mathcal{I}}_c$ corresponding to in-band transitions is directly deduced from the data and compared to the effective moment of inertia, ${\mathcal{I}}_{\mathrm{eff}}$, deduced from multiplicity measurements. For $I\sim \mathrm{}(30-45)\mathrm{}\hslash$ it is found that ${\mathcal{I}}_c$ is 25-50% smaller than ${\mathcal{I}}_{\mathrm{eff}}$, which suggests an important contribution to the total spin from a few aligned particles. This description implies band crossings for which there is independent evidence.