Abstract
A model-insensitive data-to-data formula based on an analytic expression for the scattering of a Dirac particle from a nucleus is derived for the energy dependence of the scattering. Using this formula, the Dirac impulse approximation is found to account for the energy dependence of proton scattering from Ca40 and Pb208 in the 500-800 MeV regime. The energy dependence cannot, however, be accounted for to energies below 200 MeV. The method introduced in the analysis is applicable to a wide variety of scattering problems.