2005/02/01 by Andrei V. Afanasev, Andrei Afanasev, Stanley J. Brodsky +4 · 2 citations
Physics and Astronomy · #High-Energy Particle Collisions Research #Particle physics theoretical and experimental studies #Quantum Chromodynamics and Particle Interactions #hep-ph #nucl-th
paper · pdf · doi:10.1103/physrevd.72.013008
published as Phys.Rev.D72:013008,2005 · 38 pages, 22 figures
arxiv created 2005/02/01 · openalex publication_date 2005/07/28 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
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.