Beyond the Born Approximation: The Two-Photon Exchange Experiment in CLAS

Knowledge of the electromagnetic form factors of the nucleon is crucial both for increasing our understanding of the proton and for interpreting proton knockout measurements from nuclei. However, there is a large discrepancy between proton electric form factor ($G_E(Q^2)$) measurements using the Rosenbluth separation method and ones using polarization transfer. This discrepancy increases to a factor of three at $Q^2 = 6$ GeV$^2$. One of the most plausible proposed explanations is the contribution from two-photon exchange effects to $ep$ elastic scattering. The two-photon exchange contribution is directly proportional to the deviation from unity of the ratio of the $e^{+}p$ to $e^{-}p$ elastic scattering cross sections. This ratio was measured at the Thomas Jefferson National Accelerator Facility using the CLAS detector in Hall-B in 2010-2011. The current status of the experiment is presented.