Abstract
The nuclei and were investigated in high-resolution inelastic electron scattering for momentum transfers . The complete strength could be extracted in both nuclei up to excitation energies of about 15 MeV. Second-random-phase approximation calculations successfully describe the strong fragmentation of the experimental strength distributions. Contrary to previous experimental findings, suggesting a severe reduction, the deduced quenching of spin matrix elements is comparable to the case. A quantitative reproduction of the data requires the presence of appreciable orbital strength which can be interpreted as a torsional elastic vibration (“twist mode”).
- Received 24 July 1998
DOI:https://doi.org/10.1103/PhysRevLett.82.1105
©1999 American Physical Society