Electric form factor of the neutron from theH2(e→,e’n→)1H reaction atQ2=0.255 (GeV/c)2

Abstract

We determined the electric form factor ${\mathit{G}}_{\mathit{E}}^{\mathit{n}}$ of the neutron from the quasielastic ${}_{}{}^2{}_{}{}^{}\mathrm{H}$(e→,${\mathit{e}}^{\mathcal{’}}$n→${)}^1$H reaction at a central squared four-momentum transfer ${\mathit{Q}}^2$=0.255 (GeV/c${)}^2$ with a longitudinally polarized electron beam of 868 MeV and a low (∼0.8%) duty factor. A neutron polarimeter designed and constructed specifically for this experiment was used to measure the sideways polarization of the recoil neutron, which was detected in coincidence with the scattered electron. Theoretical calculations have established that this polarization-transfer technique for quasielastic scattering produces a value of ${\mathit{G}}_{\mathit{E}}^{\mathit{n}}$ that shows little sensitivity to the influence of final-state interactions, meson-exchange currents, isobar configurations, and deuteron structure. The value for ${\mathit{G}}_{\mathit{E}}^{\mathit{n}}$ from this measurement is 0.066±0.036±0.009.