SHAPE EVOLUTION FOR Ce ISOTOPES IN RELATIVISTIC MEAN-FIELD THEORY.

The evolution of shape from the axially deformed to the spherical shapes in the Ce isotopes is investigated microscopically in relativistic mean-field theory. The microscopic and self-consistent quadruple deformation constrained relativistic mean-field calculations show a clear change for the even-even Ce isotopes with N = 62 ~ 84. The potential surfaces for ¹²⁸Ce, ¹³⁰Ce, ¹³²Ce and ¹³⁴Ce are found to be relatively flat, which may be the possible critical-point nuclei. Similar conclusions can also be drawn from the microscopic single-particle spectra. [ABSTRACT FROM AUTHOR]