Microscopic study of a C4-symmetry hypothesis in A~150 superdeformed nuclei: Deformed Woods-Saxon mean field.

Abstract

Microscopic analysis of the quantum (shell) effects related to the presence of the hexadecapole (${\mathit{Y}}_{4\mathrm{\ensuremath{\mu}}}$; \ensuremath{\mu}=0,2,4) components in the nuclear mean field is performed for the superdeformed nuclei in the mass A \ensuremath{\sim} 150 region using the deformed Woods-Saxon potential. No shell effects favoring the ${\mathit{C}}_{4}$-symmetry are found. The calculations indicate, however, the existence of the ${\mathrm{\ensuremath{\alpha}}}_{44}$-deformation driving orbitals whose occupation might induce an ${\mathrm{\ensuremath{\alpha}}}_{44}$-polarization effect. For $^{149}\mathrm{Gd}$ and $^{153}\mathrm{Dy}$ nuclei, in which the existence of the ${\mathit{C}}_{4}$-symmetry effects is suspected, properties of several excited particle-hole configuration are analyzed.