A new rigid asymmetric-rotor model description of the heavy transitional nuclei

Hexadecapole shape components have been added to the usual Davydov-Filippov asymmetric-rotor model and this extended model has been applied to the nuclei 184186W, 186188190192Os, 192194196Pt, and 198200Hg. This model provides a much improved description of the E2 properties and in addition predicts correctly the known E4 properties. E2 properties previously thought to be anomalous (phases and magnitudes of matrix elements involving the second 2+ states) are correctly predicted. (Auth.)