The systematics of experimental energy differences between the levels of the ground state band and the even levels of the ${\gamma }_1$ band in even-even nuclei are studied as a function of the angular momentum L. Three clearly different trends are seen. In deformed nuclei a decrease of the energy differences with increasing L is found. In γ-unstable and triaxial nuclei the energy differences are increasing with increasing L, but the rate of increase is larger in the triaxial case by an order of magnitude in relation to the γ-unstable case. This observation is corroborated by numerical results and analytic expressions in the framework of several special solutions of the Bohr Hamiltonian.

基态带能级和偶数能级之间的实验能量差的系统分析 ${\gamma }_{\mathrm{1个}}$研究了偶数原子核中的能带与角动量L的关系。可以看到三种明显不同的趋势。在变形的原子核中，发现随着L的增加，能量差减小。在γ不稳定和三轴核中，能量差随着L的增加而增加，但是在三轴情况下，其增加速率相对于γ不稳定的情况大一个数量级。数值结果和解析表达式在玻尔·哈密顿量的几个特殊解的框架中得到了证实。