The two-photon exchange contribution to elastic electron-nucleon scattering at large momentum transfer
Abstract
We estimate the two-photon exchange contribution to elastic electron-proton scattering at large momentum transfer by using a quark-parton representation of virtual Compton scattering. We thus can relate the two-photon exchange amplitude to the generalized parton distributions which also enter in other wide angle scattering processes. We find that the interference of one- and two-photon exchange contribution is able to substantially resolve the difference between electric form factor measurements from Rosenbluth and polarization transfer experiments. Two-photon exchange has additional consequences which could be experimentally observed, including nonzero polarization effects and a positron-proton/electron-proton scattering asymmetry. The predicted Rosenbluth plot is no longer precisely linear; it acquires a measurable curvature, particularly at large laboratory angle.
Keywords
Cite
@article{arxiv.hep-ph/0502013,
title = {The two-photon exchange contribution to elastic electron-nucleon scattering at large momentum transfer},
author = {Andrei V. Afanasev and Stanley J. Brodsky and Carl E. Carlson and Yu-Chun Chen and Marc Vanderhaeghen},
journal= {arXiv preprint arXiv:hep-ph/0502013},
year = {2008}
}
Comments
38 pages, 22 figures