Abstract
Inelastic scattering exciting the and members of the γ-vibrational band in ,154Sm, , , ,168Er, , ,184W, and has been measured with 65-MeV polarized protons. Coupled-channel analyses have been performed assuming the γ-vibrational model or the asymmetric rotor model. A large hexadecapole () term in the γ motion is necessary in both models in order to reproduce the experimental data. The quadrupole () and hexadecapole () transition strengths to the γ-vibrational band have been extracted systematically from the optical potential parameters and the deformation parameters for the first time. These show a strong mass number dependence, and can be understood qualitatively by a simple geometrical picture together with the quadrupole () and hexadecapole () moments. The experimental and strengths have been compared with a random-phase-approximation calculation. This suggests the importance of the hexadecapole degree of freedom in the γ vibration. A density-dependent Hartree-Fock calculation explains the quadrupole () moments and the trend of the hexadecapole () moments of the deformed optical potentials very well. The effect of the density dependence of the effective interaction is also discussed through the moments and strengths.
- Received 14 October 1986
DOI:https://doi.org/10.1103/PhysRevC.36.1754
©1987 American Physical Society