Electric Form Factor of the Neutron

Recent polarization-based precision measurements of the nucleons' elastic electric form factors have led to surprising results. The measurement of the ratio of the proton's electromagnetic form factors, $$\mu_p G_E^p/G_M^p$$, was found to drop nearly linearly with $Q^2$ out to at least $$5 \mathrm{GeV}^2$$, inconsistent with the older Rosenbluth-type experiments. A recent measurement of $G_E^n$, the neutron's electric form-factor saw $G_E^n$ does not fall off as quickly as commonly expected up to $$Q^2 \approx 1.5 \mathrm{GeV}^2$$. Extending this study, a precision measurement of $G_E^n$ up to $$Q^2=3.5 \mathrm{GeV}^2$$ was completed in Hall A at Jefferson Lab. The ratio $G_E^n/G_M^n$ was measured through the beam-target asymmetry $$A_\perp$$ of electrons quasi-elastically scattered off polarized neutrons in the reaction $${}^{3}\overrightarrow{He}(\overrightarrow{e},e' n)$$. The experiment took full advantage of the electron beam, recent target developments, as well as two detectors new to Jefferson Lab. The measurement used the accelerator's 100\% duty-cycle high-polarization (typically 84\%) electron beam and a new, hybrid optically-pumped polarized $${}^{3}\overrightarrow{He}$$ target which achieved in-beam polarizations in excess of 50\%. A medium acceptance (80msr) open-geometry magnetic spectrometer (BigBite) detected the scattered electron, while a geometrically matched neutron detector observed the struck neutron. Preliminary results from this measurement will be discussed and compared to modern calculations of $G_E^n$.