Inertia tensor and fine structure of scissors-mode resonances

In a recent paper it has been shown that a number of rare-earth elements have a definite deviation from axial symmetry, with the triaxiality angle $\gamma \ge 8$ degrees and the ratios of the components of the inertia tensor in qualitative agreement with the irrotational model. Such results have been extracted from experimental data within the J-2 subspace, but scissors-mode resonances, which are most sensitive to the nuclear shape, were not included in the analysis. The irrotational and rigid inertia tensors have an opposite dependence on the triaxiality angle $\gamma$ and this affects in a striking way the fine structure of scissors-mode resonances.