Electromagnetic form factors at low energy elastic electron–proton scattering

Abstract

The prediction of quantum electrodynamics for elastic electron–proton scattering needs further modifications to agree with experimental data. Two scattering mechanisms that may occur are the forward and backward scattering angles for four-momentum transfer [Formula: see text] up to 0.8 (GeV/[Formula: see text])2. This is due to two different scattering centers. But the forward scattering is observed only at relatively high values of [Formula: see text][Formula: see text](GeV/[Formula: see text])2. The modifications related to the electric and magnetic form factors characterize the proton’s internal structure. These form factors’ dependence on [Formula: see text] provides good agreement with other analysis methods. The proton’s charge radius, which corresponds to the maximum value of the scattering radius, is [Formula: see text][Formula: see text]fm. The scattered electron is sensitive to proton internal constituents, especially at high values of [Formula: see text] in which both scattering radius and photon wavelength decrease.