Triaxial strongly deformed structures in the even-even Hf nuclei

Wenchao Ma

doi:10.1051/epjconf/20146602115

Abstract

Two rotational bands of distinct character have been identified in 164 Hf from a recent experiment at Gammasphere. They are suggested to correspond to the long- anticipated triaxial strongly deformed (TSD) bands predicted by theoretical studies. The bands are substantially stronger in intensity and are located at lower spins than the pre- viously observed TSD bands in 168 Hf, and have been linked to the known states, hereby making 164 Hf the best even-even system for the study of TSD structures in the A ∼ 160 mass region. Cranking calculations based on the modified-oscillator model suggest that the bands are associated with four-quasiparticle configurations involving high-j intruder (i13/2) 2 proton orbitals. Wobbling mode has not been observed in 164 Hf and the possible reasons are discussed.

Highlights

Two rotational bands of distinct character have been identified in 164Hf from a recent experiment at Gammasphere
It has proved to be a considerable challenge to predict the behavior of triaxial strongly deformed (TSD) bands in specific nuclei, even those differing by only a single nucleon from the well-studied cases above
While the observed TSD bands in the Z = 71 Lu isotopes and N = 94 isotones are consistent with the calculated TSD shell gaps, experimental searches in both 17626Hf94 [20] and 169Hf97 [21] failed to uncover any TSD structure

Summary

Introduction

Two rotational bands of distinct character have been identified in 164Hf from a recent experiment at Gammasphere. Bands based on quasiparticle excitations have been observed in neighboring nuclei, such as 164Lu

Results

Conclusion