Abstract
A study of states in was carried out by observing these states as resonances in the compound system + The lowest state was observed as a resonance in the proton elastic scattering at MeV. A search for additional states was carried out by measuring excitation functions for elastic scattering and for several proton-induced reactions over the proton energy range 17.0-21.5 MeV; two anomalies were found at MeV, whose widths and locations suggest that they might correspond to states. In order to obtain the spins, parities, and elastic partial widths for the observed resonances, a program of phase-shift analysis was carried out using optical-model phases plus a single-level dispersion term. Such an analysis of the 14.231-MeV resonance yielded the assignment of . From a similar analysis, one obtains for the 17.80-MeV resonance, while the 18.459-MeV resonance was limited to spin and parity assignments of or . These assignments for the 17.80- and 18.459-MeV resonances, and the observed intensities for their proton decay to the 15.11-MeV state in are consistent with their identification as states. Five other resonances, thought to correspond to states, were observed at MeV and were also analyzed in a similar fashion to yield spin and parity assignments of , , , , and , respectively.
- Received 2 May 1969
DOI:https://doi.org/10.1103/PhysRev.186.1021
©1969 American Physical Society