Measurement of the Neutron Electric to Magnetic Form Factor Ratio atQ2=1.58  GeV2Using the ReactionHe→3(e→,e′n)pp

2013

A measurement of beam helicity asymmetries in the reaction $^{3}\stackrel{\ensuremath{\rightarrow}}{\mathrm{He}}(\stackrel{\ensuremath{\rightarrow}}{e},{e}^{\ensuremath{'}}n)pp$ is performed at the Mainz Microtron in quasielastic kinematics to determine the electric to magnetic form factor ratio of the neutron ${G}_{E}^{n}/{G}_{M}^{n}$ at a four-momentum transfer ${Q}^{2}=1.58\text{ }\text{ }{\mathrm{GeV}}^{2}$. Longitudinally polarized electrons are scattered on a highly polarized $^{3}\mathrm{He}$ gas target. The scattered electrons are detected with a high-resolution magnetic spectrometer, and the ejected neutrons are detected with a dedicated neutron detector composed of scintillator ba…