The low-lying dipole strength distribution in the rare isotope 176Hf was studied in nuclear resonance fluorescence experiments performed at the Stuttgart Dynamitron facility using bremsstrahlung beams with end- point energies of 4.1 and 2.4 MeV. In total, about 55 excited spin-1 states, unknown so far, were observed in the excitation energy range up to 4 MeV. Detailed spectroscopic information has been obtained on excitation energies, spins, decay widths, decay branchings, and transition probabilities. Ascribing a positive parity to all observed K=1 states, the detected total B(M1)↑ strength in the energy range of the scissors mode amounts to 2.56(6)μ2N, nearly as much as for well-deformed midshell rare-earth nuclei. The total strength is higher than in the heavier Hf isotopes 178,180Hf, but fits well into the systematics. The observed low-lying ΔK=0 transitions (with probable E1 character) lie in the energy range around 2 MeV, as expected from the systematics. The excitation probabilities correspond to values which are characteristic for nuclei in the transitional region from deformed rotors to more γ-soft nuclei.
Scheck, M., Belic, D., von Brentano, P., Carroll, J. J., Fransen, C., Gade, A., von Garrel, H., Kneissl, U., Kohstall, C., Linnemann, A., Pietralla, N., Pitz, H. H., Stedile, F., Toman, R., & Werner, V. (2003). Photon scattering experiments off Hf-176 and the systematics of low-lying dipole modes in the stable even-even Hf isotopes Hf-176,Hf-178,Hf-180. Physical Review C, 67(6), . https://doi.org/10.1103/PhysRevC.67.064313