Elastic Electron-Proton Scattering at Large Four-Momentum Transfer

Electron-proton elastic-scattering cross sections have been measured at the Stanford Linear Accelerator Center for four-momentum transfers squared $q^{ 2}$ from 1.0 to 25.0 ${\left(\frac{\mathrm{GeV}}{c}\right)}^2$. The electric ($G_{E_p}$) and magnetic ($G_{M_p}$) form factors of the proton were not separated, since angular distributions were not measured at each $q^{ 2}$. However, values for $G_{M_p}$ were derived assuming various relations between $G_{E_p}$ and $G_{M_p}$. Several theoretical models for the behavior of the proton magnetic form factor at high values of $q^{ 2}$ are compared with the data.