Superdeformed Bands with ΔI = 4 Bifurcation of theOdd-A Nuclei in the A~190 Region

Abstract

The γ-ray energy (Eγ) spectra of the superdeformed (SD)bands of odd-A nuclei in the A~190 mass region areinvestigated systematically. It is found that a ΔI = 4 bifurcationexists in the SD bands. Within the supersymmetry scheme includingmany-body interactions and a perturbation possessing the SO(5) (orSU(5)) symmetry on the rotational symmetry, the Eγ spectra,dynamical moments of inertia and Eγ differences δ4Eγ(I) of these bands are evaluated. Quantitative good results areobtained which show that the scheme is powerful to describe the ΔI = 4 bifurcation. The ΔI = 4 bifurcation may then come from theperturbation holding the SO(5) (or SU(5)) symmetry on the rotation.From a microscopic point of view, the ΔI = 4 bifurcation may be aresult of the combination of the β-phonon, γ-phonon and therotation.