Triaxial rotor model description of E2 properties in Os186,188,190,192

The triaxial rotor model with independent inertia and electric quadrupole tensors is applied to the description of the extensive set of E2 matrix elements available for Os186,188,190,192. Most large and medium transition E2 matrix elements can be reproduced to within ~10%, and most diagonal elements to within ~30%. Most small transition matrix elements can be reproduced to within ~30%, and they support the interference effect exhibited by the model between the inertia and E2 tensors: this is a new feature of quantum rotor models. The diagonal E2 matrix elements at higher spins in the K=2 band are extremely sensitive to admixtures of higher K values: the low experimental values in Os190,192 indicate significant admixtures of K=4 components. Attention is given to the Kπ=4+ bands in these nuclei and the controversial issue of whether they are of quadrupole or hexadecapole nature.