The optical potential and observables for proton${\mathrm{-}}^{9,11}$Li elastic scattering are calculated microscopically using the single scattering approximation to the Kerman-McManus-Thaler multiple scattering expansion. The importance of the central and spin-orbit terms of the optical potential, and of the core and halo nucleon contributions, is clarified in terms of the momentum space behaviors of the nucleon-nucleon amplitudes and relevant density distributions. Calculations for the ${}_{}{}^9{}_{}{}^{}\mathrm{Li}$ and ${}_{}{}^{11}{}_{}{}^{}\mathrm{Li}$ systems at 60 and 62 MeV/nucleon, respectively, are compared with the available experimental data and with calculations and data for the proton${\mathrm{-}}^8$He system at similar energy. Three-body models of ${}_{}{}^{11}{}_{}{}^{}\mathrm{Li}$ are used. The effects of the halo distribution in ${}_{}{}^{11}{}_{}{}^{}\mathrm{Li}$ are clearly manifest in the elastic cross section but there are small differences between observables for structure models with realistic two-neutron asymptotic behaviors. Calculations suggest that the ${}_{}{}^9{}_{}{}^{}\mathrm{Li}$ core structure is not realistically described by simple models. © 1996 The American Physical Society.

• Received 11 December 1995

DOI:https://doi.org/10.1103/PhysRevC.54.1867