Abstract
A detailed study of the de-excitation of gamma emitting states in at 8.87, 10.94, and 11.06 Mev has been carried out using the reaction. Branching ratios and angular distribution measurements on both proton groups and gamma radiations strongly suggest assignments , , and , respectively, although in the latter case the possibility is not excluded. The experimental results are compared with predictions of the alpha-particle and intermediate-coupling shell models. While considerable areas of agreement exist, serious discrepancies remain in both cases. The identification of the , 10.94-Mev state precludes Dennison's preferred "identification (a)" in the alpha-particle model and fixes the exchange mixture in the shell model calculations; the mixture closely resembles a Serber rather than the Rosenfeld mixture commonly in use in these shell model calculations. From the measured de-excitation branching ratio for the 10.94-Mev state and the systematics of gamma-radiation and alpha-particle transition widths, an upper limit of ∼2× is obtained for the relative intensity of an opposite-parity component in the wave function of this state.
- Received 15 December 1958
DOI:https://doi.org/10.1103/PhysRev.114.758
©1959 American Physical Society