Excitation functions and angular distributions have been measured with high resolution for inelastic scattering to the $0^{+}$ 6.050-MeV, $3^{-}$ 6.131-MeV, $2^{+}$ 6.919-MeV, and $1^{-}$ 7.119-MeV states in ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$ near the $E_{\mathrm{c}.\mathrm{m}.\mathrm{}}=19.7\mathrm{}$-MeV resonance in the ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$+${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$ system. The $0^{+}$ and $2^{+}$ states show no resonant behavior whereas the $3^{-}$ state does. These results do not support an explanation for the $E_{\mathrm{c}.\mathrm{m}.\mathrm{}}=19.7\mathrm{}$-MeV resonance which involves an $\alpha$-particle exchange mechanism.

NUCLEAR REACTIONS ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$(${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$, ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$), measured $\sigma (E,\theta )$ for 6.050-, 6.131-, 6.919-, 7.119-MeV levels in ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$, $E=44.4\mathrm{}-48.0$ MeV, $\theta =5\mathrm{}-15°$, resolution 45-65 keV.

• Received 24 September 1975

DOI:https://doi.org/10.1103/PhysRevC.13.447