Transition quadrupole moments in gamma-soft nuclei and the triaxial projected shell model

Transition probabilities of the ground-state bands in gamma -soft nuclei ar e studied for the first time using the triaxial projected shell model appro ach. It is observed that the angular-momentum dependence of the transition quadrupole moment Pf is related to the triaxial deformation of the nuclear mean-field potential. The introduction of the gamma -degree of freedom in t he shell model basis is shown to have a little influence on the constant be havior of the low-spin Pt in a well-deformed nucleus. However. the increasi ng collectivity with spin for the low-spin states in a gamma -soft nucleus can only be explained by considering the triaxial mean-field deformation. ( C) 2001 Elsevier Science B.V. All rights reserved.