Existence of Triaxial Shapes in Transitional Nuclei

Three-dimensional exact angular momentum projection is used to investigate the shape of transitional nuclei. It is found that in cases in which the unprojected energy surfaces are almost $\gamma$ unstable, angular-momentum-projected energy surfaces show pronounced minima having triaxial shapes, in which a large fraction of the wave function localizes in the region ${20}^{\circ }<~\gamma <~{40}^{\circ }$.