Extraction of structure functions from quasielastic electron scattering (e,e^') off medium and heavy nuclei

Using a relativistic mean-field single-particle knockout model for (e,e^') reactions on nuclei, we investigate approximate treatments of Coulomb distortion effects and the extraction of longitudinal and transverse structure functions. We show that an effective momentum approximation when coupled with a focusing factor provides a good description of the transverse contributions to the (e,e^') cross sections for electron energies above 300 MeV on ²⁰⁸Pb. This approximation is not as good for the longitudinal contributions even for incident electron energies above 1 GeV, and if one requires very precise extraction of longitudinal and transverse structure functions in the quasielastic region, one must utilize distortion factors based on a nuclear model and a more accurate inclusion of Coulomb distortion effects.