Measurement of the electric form factor of the neutron through d^→(e^→, e′n)p at Q² = 0.5(GeV/c)²

We report the first measurement using a solid polarized target of the neutron electric form factor GnE via d→(e→, e′n)p. GnE was determined from the beam-target asymmetry in the scattering of longitudinally polarized electrons from polarized deuterated ammonia (15ND3). The measurement was performed in Hall C at Thomas Jefferson National Accelerator Facility in quasifree kinematics with the target polarization perpendicular to the momentum transfer. The electrons were detected in a magnetic spectrometer in coincidence with neutrons in a large solid angle segmented detector. We find GnE = 0.04632 ±0.00616(stat)±0.00341(syst) at Q2 = 0.495 (GeV/c)2. © 2001 The American Physical Society.