Elastic scattering data for proton scattering from ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$ are analyzed phenomenologically by use of local, complex, one-channel optical-model potentials and in an extended coupled-reaction-channel environment. Although the back-coupling amplitudes in the elastic channel from pickup-stripping paths through ${}_{}{}^{11}{}_{}{}^{}\mathrm{C}$ intermediate states are found to be quite sizable, the optical-model potential is able to simulate most of the effects quite well for both scattering and reaction processes at energies greater than about 60 MeV. The parameters of the optical-model potential and the residual optical-model potential of the coupled-reaction-channel environment are found to vary smoothly with energy. Below 60 MeV, these parameters have quite different trends and the ability of the one-channel optical-model potential to simulate the singular effects of strong couplings is much reduced.

NUCLEAR REACTIONS ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$+$p$ system, energies up to 185 MeV; optical-model phenomenological analysis; coupled-reaction-channel analysis; comparison with DWBA calculations.

• Received 1 October 1979

DOI:https://doi.org/10.1103/PhysRevC.21.2162