Measurement of Elastic Electron Scattering from the Proton at High Momentum Transfer

Abstract

We have performed absolute measurements of the differential cross section for elastic $e\ensuremath{-}p$ scattering in the range of momentum transfer from ${Q}^{2}=2.9 \mathrm{to} 31.3$ ${(\mathrm{G}\mathrm{e}\mathrm{V}/\mathit{c})}^{2}$. Combined statistical and systematic uncertainties in the cross-section measurements ranged from 3% at low ${Q}^{2}$ to 19% at high ${Q}^{2}$. These data have been used to extract the proton magnetic form factor ${G}_{M}^{p}({Q}^{2})$. The results show a smooth decrease of ${Q}^{4}{G}_{M}^{p}$ with momentum transfer above ${Q}^{2}=10$ ${(\mathrm{G}\mathrm{e}\mathrm{V}/\mathit{c})}^{2}$. These results are compared with recent predictions of perturbative QCD.