$Q^2$ dependence of Two Photon Exchange Effects at $\epsilon=0.884$

A large discrepancy has been observed between proton electromagnetic form factor ratios $G^p_E/G^p_M$ measured by Rosenbluth separation and polarization transfer experiments. One possible source of this discrepancy is effects due to two-photon exchange (TPE) not being properly accounted for in radiative corrections. We have used a mixed beam of electrons and positrons elastically scattered from a liquid hydrogen target in the CLAS detector at Jefferson Lab to determine the cross section ratio $R=\sigma(e^+p)/\sigma(e^-p)$. This ratio provides a model-independent method of determining the TPE effects in elastic electron scattering. This talk will present the motivation for this measurement and the experimental method used to extract $R$. We will present for the first time results showing the $Q^2$ dependence of $R$ at an average $\epsilon=0.884$ for $0.3\leq Q^2\leq 1.25$ GeV$^2$. The implications of the results will be discussed.