A measurement of two-photon exchange in unpolarized elastic electron-proton scattering

Jefferson Lab experiment E05-017 was designed to study 2-photon exchange contributions to elastic electron-proton scattering over a wide kinematic range. By detecting the scattered proton instead of the electron these measurements will be very sensitive to the $\epsilon$ dependence of the cross section and consequently the ratio $\frac{G_E}{G_M}$. The goals of the experiment, the experimental technique and the kinematic range will be presented. The analysis sequence and results of the early steps will be outlined.