Abstract
Evidence of strong coupling of quasiparticle excitations with vibration is shown to occur in transitional nuclei. High-spin band structures in Er are studied by employing the recently developed multiquasiparticle triaxial projected shell model approach. It is demonstrated that a low-lying band observed in these nuclei, the nature of which has remained unresolved, originates from the angular-momentum projection of triaxially deformed two-quasiparticle (qp) configurations. Furthermore, it is predicted that the structure of this band depends critically on the shell filling: in Er the lowest 2-qp band is formed from proton configuration, in Er the neutron and proton 2-qp bands are almost degenerate, and for Er and Er the neutron 2-qp band becomes favored and can cross the -vibrational band at high rotational frequencies. We consider that these are a few examples in even-even nuclei, where the three basic modes of rotational, vibrational, and quasiparticle excitations coexist close to the yrast line.
- Received 9 September 2011
DOI:https://doi.org/10.1103/PhysRevC.84.054314
©2011 American Physical Society