Search for evidence of two-photon contribution in elastic electron-proton data

We reanalyze the most recent data on elastic electron-proton scattering. We look for deviation from linearity of the Rosenbluth fit to the differential cross section, which would be the signature of the presence of two-photon exchange. The two-photon contribution is parametrized by a one-parameter formula, based on symmetry arguments. The present data do not show evidence for such deviation.