High-accuracy comparison of electron and positron scattering from nuclei

We compare the elastic-scattering cross sections for electrons and positrons from {sup 208}Pb and {sup 12}C. The results demonstrate that the electron-nucleus interaction can be described to good accuracy as a single hard-photon exchange process, and validate the theoretical framework used to interpret electron-scattering data in terms of ground-state charge densities of nuclei.