ON THE QUESTION OF SPIN FITTING AND QUANTIZED ALIGNMENT IN ROTATIONAL BANDS

Several methods employed to parametrize the spins of the superdeformed bands in terms of their observed gamma-ray energies are closely examined. It is pointed out that, since the proposed fitting procedures are variants of the Harris expansion formula, it is questionable if they could be applied to determine the unknown spins of the excited bands due to the possible presence of non-zero initial alignments. A comprehensive study of the normally deformed excited bands indicates that no correlation exists between the fitted spins and the experimentally known values. By analogy, we may conclude that there is no firm evidence for the presence of anomalous relative alignments between the superdeformed identical bands in the Hg region. Additionally, a critical review of several of the models and scenarios that purport to explain the origin of the identical bands, or the patterns of the fitted alignments is presented. It is concluded that none of these models can satisfactorily explain the identical moments of inertia in neighboring nuclei and the systematics of the observed or fitted alignments. Thus, the important question of the microscopic origin of the identical bands remains to be investigated.