The PtOs nuclei are treated from the viewpoint of the interacting boson approximation model, in particular, as a region initiating an O(6) → rotor transition. It is found that the levels and level patterns predicted in the O(6) limit occur in these nuclei and that the trends in a large number of rapidly varying B(E2) values and E2 branching ratios can be reproduced by calculations that are sensitive almost solely to a single parameter representing the relative location of a nucleus between the O(6) and rotor extremes. This parameter is chosen to vary smoothly and systematically. Specifically, the striking empirical differences in the decay modes of 0+ states in Pt and Os emerge as natural and nearly parameter independent consequences of the changes in boson number with mass. Other characteristics features of the O(6) → rotor transition, such as the behavior of 0+-2+-2+ sequences, the emergence of K = 4 rotational bands in Os and the rapidly changing branching ratios involving the quasi-γ-band all reflect corresponding empirical trends in this region. Further, the perturbed O(6) scheme predicts absolute B(E2) values which, over the entire region, agree much better with the data than those of existing models.
All Science Journal Classification (ASJC) codes
- Nuclear and High Energy Physics