Possible superdeformed states in rare earth nuclei studied using the Nilsson and Woods-Saxon potentials

Abstract

Shell effects accompanying fast rotation are examined using the cranked Nilsson and Woods-Saxon average nuclear potentials. The single particle states in strongly elongated nuclei (with a quadrupole deformation β 2 ≈ 0.65 equivalent to the axis ratio 2 : 1) are analysed. From the relatively large gaps in the single-particle spectra of rotating nuclei the proton and neutron magic numbers are deduced ( Z = 64, 66, 75, 76; N = 82, 88) which correspond to shell closures at large deformations and high spins. The nuclear spin values associated with the superdeformed states estimated from the Woods-Saxon spectra are roughly 30 to 40 percent lower than the ones obtained within the Nilsson model. This discrepancy is attributed to the presence of the l 2 term in the Nilsson potential.