Abstract
Beams of 96- and 115-MeV particles were used to study the giant resonance region in 27 nuclei ranging from to A prominent broad ( MeV) peak is present in the spectra at an excitation energy of MeV for all nuclei studied with . No such prominent peak is apparent for . The angular distributions of the peak are characterized by an oscillatory behavior which is quite different from the monotonic behavior of the background. Distorted wave calculations with reproduce the experimental angular distributions quite well for most of the nuclei. Energy weighted-sum rule fractions range from 30-50% for the lighter targets to near 100% for the heavier targets. Distorted wave calculations with a breathing mode () form factor fail to reproduce the observed resonance strength by about a factor of 3 for all targets. The width of the peak is smallest for the closed shell nuclei , , , and . A small but significant broadening is observed in the rare-earth region of deformed nuclei. The giant dipole resonance is not appreciably excited for any of the targets.
NUCLEAR REACTIONS , , , , , , , , , , , , , , , , , , , , , , , MeV. Measured , giant resonances. Deduced , .
- Received 13 August 1975
DOI:https://doi.org/10.1103/PhysRevC.13.994
©1976 American Physical Society