Triaxial shape in Os-Pt region from ground states to collective rotational states

In order to study the deformation of the nuclei which belongs to the transitional region between strongly deformed and spherical nuclei, the calculations of the total Routhian surfaces by means of the pairing-deformation- frequency self-consistent cranked shell model were carried out in order to investigate shape evolution in even-mass Os and Pt isotopes ( 176-202Os and 182-204Pt) starting from the static nuclear ground states. It is found that some nuclear ground states such as in 196Os and 188-194Pt are neither oblate nor prolate. Instead, the ground-state minima in these nuclei are axially asymmetric in shape. In addition, a complementary approach is used to extract equilibrium γ0 value (nonaxially symmetric equilibrium shape parameter), which support our predictions. © 2010 World Scientific Publishing Company