STATISTICAL ORIENTATION FLUCTUATIONS IN HOT ROTATING NUCLEI

Statistical fluctuations in the orientation of the shape relative to the rotation axis are calculated with the j = 13/2 model and the Landau model. The fluctuations are determined with two alternative assumptions: (i) the rotational frequency remains constant as the shape orientation fluctuates, and (ii) the average angular momentum remains constant as the shape orientation fluctuates. These two constraints produce different orientation probability distributions. The dynamic inertia tensor and the kinematic inertia tensor both give principal moments of inertia which depend upon the orientation of a deformed potential relative to the rotation axis. This phenomenon is caused by single-particle level crossings, which are induced by variations in the orientation.