DESCRIPTION OF EVEN-EVEN TRIAXIAL NUCLEI WITHIN THE COHERENT-STATE AND THE TRIAXIAL ROTATION-VIBRATION MODELS

The coherent state model (CSM) and the triaxial rotation-vibration mod el (TRVM) are alternatively used to describe the ground, gamma and bet a bands of Th-228. CSM is also applied to the nuclei Xe-126 and Ba-130 , which were recently considered in TRVM, The two models are compared with respect to both their underlying assumptions and to their predict ed results for energy levels and E2 branching ratios. Both models desc ribe energies and quadrupole transitions of Th-228 equally well and in good agreement with experiment, if the 0(3)(+) level at 1120 keV is i nterpreted as the head of the beta band. The other two 0(+) levels at 832 and 939 keV are most likely not of a pure quadrupole vibration nat ure as has been already pointed out in the literature, (C) 1998 Elsevi er Science B.V.