Two direct search methods have been applied to extract the optimum optical-model parameters for the elastic scattering of ${}_{}{}^{14}{}_{}{}^{}\mathrm{N}$ by ${}_{}{}^{12,13,14}{}_{}{}^{}\mathrm{C}$, ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$ by ${}_{}{}^{13,14}{}_{}{}^{}\mathrm{C}$, and ${}_{}{}^{13}{}_{}{}^{}\mathrm{C}$ by ${}_{}{}^{14}{}_{}{}^{}\mathrm{C}$ for center-of-mass energies in the range 7.8 to 12.6 MeV. The success of the analysis suggests that it is possible to interpret these data in terms of an optical-model potential alone, indicating that such experiments do not provide unambiguous evidence for interference between the elastic-scattering and elastic-transfer modes.

• Received 10 April 1975

DOI:https://doi.org/10.1103/PhysRevLett.34.1468