Inelastic Electron Scattering , Asymptotic Behavior , and Sum Rules

Electron scattering from a hadron target has a singularly attractive feature relative to the various processes of hadrons scattering from hadron targets: the electromagnetic field generated during the electrons’s scattering is understood if indeed anything is in particle physics. Dirac’ tells us the transition current of the ,scattered electron and Maxwell tells us the rest. Therefore, in this process we are probing the structure of the hadron by means of a known operator the electromagnetic current operator. There is an additional advantage in studying this process and that is its weakness. We can do our theoretical analyses to lowest order in the fine structure constant a! x1/137 which is a comfortable expansion parameter for quantitative results. The first detailed high energy experimental studies of electron scattering from hydrogen targets concentrated on the elastic process e+p-e’+p’ and measured the elastic form factors defined by