Proton Form Factors from Observation of Recoil Protons

Abstract

A determination of the electric and magnetic form factors of the proton has been made by studying the elastic scattering of electrons from a polyethylene target by observation of the recoiling proton at 0\ifmmode^\circ\else\textdegree\fi{} and 30\ifmmode^\circ\else\textdegree\fi{} for values of ${q}^{2}$ between 1 and 1.8 ${\mathrm{F}}^{\ensuremath{-}2}$. From these measurements we have deduced the charge radius ${R}_{c}$ and the magnetic radius ${R}_{m}$ of the proton and find equality within the experimental errors (${R}_{c}=0.800\ifmmode\pm\else\textpm\fi{}0.025$ F; ${R}_{m}=0.810\ifmmode\pm\else\textpm\fi{}0.029$ F).