Subtracted dispersion relation formalism for the two-photon exchange   correction to elastic electron-proton scattering: comparison with data
  We apply a subtracted dispersion relation formalism with the aim to improve predictions for the two-photon exchange corrections to elastic electron-proton scattering observables at finite momentum transfers. We study the formalism on the elastic contribution, and make a detailed comparison with existing data for unpolarized cross sections as well as polarization transfer observables. 
O. Tomalak, M. Vanderhaeghen (JGU Mainz)
hep-ph nucl-th