Theoretical study of normal deformed rotational bands of odd-mass ${}^{167,169,171}$Lu nuclei

Abstract

The theoretical description of nuclear structure in rare earth nuclei represents a significant challenge for many shell models. This difficulty stems from the size of the configuration space involved. Methods based on symmetries provide significant advantages. Furthermore, the pseudo-SU(3) shell model has proven to be very useful in the description of these systems. In particular, we propose to study the energy spectra of the rotational bands with normal deformation at low and medium spin ($J\le 35/2$), the quadrupole moments, and the deformation parameter $\gamma$ associated with the states, as well as the B(E2) transition strengths in the ${}^{167,169,171}$Lu nuclei. The Hamiltonian includes $Q\cdot Q$, Nilsson, and pairing terms, parameterized in a systematic way, in addition to three rotor-like terms that enable fine tuning of the spectra. Our calculations predict collective rotational bands with prolate normal deformation in most cases. The exception is the $1/2^{+}$ band in ${}^{171}$Lu with a triaxial shape. The quadrupole moments vary along the bands, increasing in absolute value with spin. The $\gamma$ deformation parameter remains nearly constant along the bands, and the B(E2) values suggest bands with collective character and normal deformation. The agreement and limitations of the model are discussed.

Comments: 9 pages (published version)