An experiment performed on the early implementation of the GAMMASPHERE array to populate the high-spin states in ${}_{}{}^{133}{}_{}{}^{}\mathrm{Ce}$ has revealed the presence of several rotational structures with energy spacings of Δ${\mathit{E}}_{\gamma }$∼100 keV. Some of these bands exhibit a backbend at ħω∼0.6 MeV and are observed to high rotational frequencies—ħω∼0.85 MeV. These characteristics are very different from those observed for any other rotational bands in this mass region. The properties of these new structures will be discussed within the framework of cranked Strutinsky-Woods-Saxon calculations. Currently, these bands are thought to be based on triaxial nuclear shapes. © 1996 The American Physical Society.

• Received 25 January 1996

DOI:https://doi.org/10.1103/PhysRevC.54.613