Nuclear structure of 154,156Dy in the dynamic pairing-plus-quadrupole model.

Abstract

The level structure and grouping into quasibands of $^{154}\mathrm{Dy}$ and $^{156}\mathrm{Dy}$ is derived in the dynamic pairing-plus-quadrupole model and the analysis is extended to five quasibands in $^{154}\mathrm{Dy}$ and seven collective K bands in $^{156}\mathrm{Dy}$. The absolute E2 moments, relative B(E2) values for interband transitions and X(E0/E2) are compared with experimental data and the predictions from the boson expansion model and the interacting boson model. The transition at N=88--90 for all observed quantities is reproduced. The anomaly of small ${0}_{g}$-${2}_{\ensuremath{\beta}}$ strength in $^{156}\mathrm{Dy}$ is explained from our analysis, retaining the collective \ensuremath{\beta}-vibration character.