Effective theory for deformed nuclei

Here, I ≥ I0 denotes the angular momentum, A is a constant determined by fit to data, and I0 is the spin of the band head under consideration. Rotational states are the lowestlying excitations in nuclei far away from closed shells. Our understanding of nuclear rotations is based on the groundbreaking work by Bohr and Mottelson [1], its extension within the general collective model [2], and the interacting boson model [3]. These phenomenological models describe a large body of experimental data. However, as with all models, they are unable to provide us with theoretical error estimates or with systematic ways of improvement.