Abstract
The giant electric dipole resonances based on the ground state () and first excited state () of have been studied with the reactions and over the range MeV. Both resonances show a simple resonant shape with little fine structure. The giant resonance is displaced upward from the resonance by an energy of 2.2 MeV which is approximately equal to the excitation of the state. The reduced () strengths of the two resonances are approximately equal and each exhausts about 10% of the sum rule. The angular distributions for both and are quite constant over the giant resonance structure and are predominantly dipole in character. A simple model can be invoked to explain the dominant features. The presence of and terms in both angular distributions indicates strength which probably increases above the resonances. Some parameters for the narrow levels at 18.15 and 19.06 MeV in are given.
NUCLEAR REACTIONS , MeV; measured . Deduced properties levels at MeV and , giant resonances. 99% enriched target.
- Received 21 January 1976
DOI:https://doi.org/10.1103/PhysRevC.14.28
©1976 American Physical Society