The possible existence of shape-coexisting nuclear configurations with tetrahedral symmetry is receiving increasing attention due to unprecedented nuclear structure properties, in particular, in terms of the exotic fourfold nucleonic level degeneracies and the expected long lifetimes, which may become a new decisive argument in the exotic nuclei research programs. The present article addresses the rotational structure properties of the tetrahedrally symmetric even-even core configurations coupled with a single valence nucleon. We focus on the properties of the associated Coriolis-coupling Hamiltonian proposing the solutions based on the explicit construction of the bases of the irreducible representations of the tetrahedral point-group on the one-hand side and the microscopic angular-momentum and parity projection nuclear mean-field approach on the other. It is shown that for one particle occupying an orbital belonging to the E1/2 or E5/2 irreducible representation, the rotational spectrum splits into two sequences, the structures analogous to those of the K=1/2 rotational bands in the axially symmetric nuclei. Although the spectrum is generally more complicated for one-particle occupying a fourfold degenerate orbital belonging to the G3/2 representation, an appearance of the correlated double-sequence structures persists. The spectra of the doubly-magic tetrahedral core plus one-particle systems can be well interpreted using the analytical solutions of the first order Coriolis-coupling Hamiltonian. We introduce the notion of the generalized decoupling parameters, which determine the size of the energy-splitting between the double-sequence structures.
All Science Journal Classification (ASJC) codes
- Nuclear and High Energy Physics