Rotational constants of multi-phonon bands in an effective theory for deformed nuclei

We consider deformed nuclei within an effective theory that exploits the small ratio between rotational and vibrational excitations. For even-even nuclei, the effective theory predicts small changes in the rotational constants of bands built on multi-phonon excitations that are linear in the number of excited phonons. In Er-166,Er-168, this explains the main variations of the rotational constants of the two-phonon gamma vibrational bands. In Th-232, the effective theory correctly explains the trend that the rotational constants decrease with increasing spin of the bandhead. We also study the effective theory for deformed odd nuclei. Here, time-odd terms enter the Lagrangian and generate effective magnetic forces that yield the high level densities observed in such nuclei. DOI: 10.1103/PhysRevC.87.034323