Empirical model with independent variable moments of inertia for triaxial nuclei applied to Ge76 and Os192

Abstract

An empirical model with independent variable moments of inertia for triaxial nuclei is devised and applied to $^{76}\mathrm{Ge}$ and $^{192}\mathrm{Os}$. Three intrinsic moments of inertia, ${J}_{1}$, ${J}_{2}$, and ${J}_{3}$, are varied independently as a particular function of spin $I$ within a revised version of the triaxial rotor model so as to reproduce the energy levels of the ground-state, $\ensuremath{\gamma}$, and (in the case of $^{192}\mathrm{Os}$) ${K}^{\ensuremath{\pi}}={4}^{+}$ bands. The staggering in the $\ensuremath{\gamma}$ band is well reproduced in both phase and amplitude. Effective $\ensuremath{\gamma}$ values are extracted as a function of spin $I$ from the ratios of the three moments of inertia. The eigenfunctions and the effective $\ensuremath{\gamma}$ values are subsequently used to calculate the ratios of $B(E2)$ values associated with these bands. Good agreement between the model calculation and the experimental data is obtained for both $^{76}\mathrm{Ge}$ and $^{192}\mathrm{Os}$.