Energies for three positive and three negative parity bands predicted by the extended coherent state model in ${}^{218,226}\mathrm{Ra},$ ${}^{228}\mathrm{Th},$ ${}^{232}\mathrm{Th},$ in four uranium even-mass isotopes, ${}^{232-238}\mathrm{U},$ and in ${}^{238}\mathrm{Pu},$ are calculated and used to point out new signatures for octupole deformation in ground as well as in $\beta$ and $\gamma$ bands. A beat pattern is found by using a new displacement energy function, which is more appropriate for a spectrum that exhibits large deviations from a linear $J(J+1\mathrm{})\mathrm{}$ dependence.

• Received 21 October 2002

DOI:https://doi.org/10.1103/PhysRevC.67.044312