Hexadecapole deformation and rotation-particle coupling in the rare earth nuclei

Abstract

Calculations of the energy spectra for odd- A nuclei in the rare earth region have been made using a rotational model for deformed nuclei. Both pairing and band mixing have been included in detail. A hexadecapole ( P 4 ) deformation was considered in addition to the usual quadrupole ( P 2 ) deformation. In most cases, this additional hexadecapole deformation proved to be quite necessary to achieve a good fit to the experimental spectra. Thirty nuclei in this region were investigated. Good results were obtained for twenty-seven. With the parameters found in achieving a fit to the energy spectra, reduced transitions rates and spectroscopic factors were calculated. Band mixing made it possible to investigate K -for-bidden transitions. In most cases there was good agreement with experimental values.