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Related papers: Two-photon exchange at low Q^2

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We evaluate the two-photon exchange (TPE) correction to the muon-proton elastic scattering at small momentum transfer. Besides the elastic (nucleon) intermediate state contribution, which is calculated exactly, we account for the inelastic…

High Energy Physics - Phenomenology · Physics 2016-03-23 O. Tomalak , M. Vanderhaeghen

We compute the two photon exchange contributions to elastic scattering of polarized electrons from target protons. We use a nonlocal field theory formalism for this calculation. The formalism maintains gauge invariance and provides a…

High Energy Physics - Phenomenology · Physics 2008-12-18 Pankaj Jain , Satish D. Joglekar , Subhadip Mitra

We investigate the effect of two-photon exchange processes upon the rms- and Zemach radii extracted from electron-proton scattering. We find that the changes are small and do not help to explain the discrepancy between experimental and…

Nuclear Theory · Physics 2008-11-26 Peter G. Blunden , Ingo Sick

We calculated two--photon exchange effects for elastic electron--proton scattering at high momentum transfers. The corresponding nucleon Compton amplitude is defined by two space--like virtual photons that appear to have significant…

High Energy Physics - Phenomenology · Physics 2017-08-23 Andrei Afanasev , Igor Akushevich , N. P. Merenkov

We calculate two-photon exchange (TPE) amplitudes for the elastic electron-proton scattering, and take into account intermediate hadronic states containing \pi N system with total angular momentum 1/2 or 3/2, which includes 8 different…

High Energy Physics - Phenomenology · Physics 2015-09-16 Dmitry Borisyuk , Alexander Kobushkin

We discuss two-photon exchange (TPE) in elastic electron scattering off the trinucleon systems, 3He and 3H. The calculations are done in the semirelativistic approximation with the trinucleon wave functions obtained with the Paris and…

Nuclear Theory · Physics 2013-10-30 A. P. Kobushkin , Ju. V. Timoshenko

We report on a new measurement of the beam transverse single spin asymmetry in electron-proton elastic scattering, $A^{ep}_{\perp}$, at five beam energies from 315.1 MeV to 1508.4 MeV and at a scattering angle of $30^{\circ} < \theta <…

We present an exact evaluation of the two-photon exchange contribution to the elastic lepton-proton scattering process at low-energies using heavy baryon chiral perturbation theory. The evaluation is performed including next-to-leading…

High Energy Physics - Phenomenology · Physics 2023-11-30 Poonam Choudhary , Udit Raha , Fred Myhrer , Dipankar Chakrabarti

We construct a nonlocal gauge invariant Lagrangian to model the electromagnetic interaction of proton. The Lagrangian includes all allowed operators with dimension up to five. We compute the two photon exchange contribution to elastic…

High Energy Physics - Phenomenology · Physics 2008-11-26 Pankaj Jain , Satish D. Joglekar , Subhadip Mitra

We systematically calculate the radiative corrections of order $\alpha/\pi$ to elastic muon-proton scattering at low momentum transfers. These include vacuum polarization, photon-loop form factors of the muon and the proton, two-photon…

High Energy Physics - Phenomenology · Physics 2022-04-20 Norbert Kaiser , Yong-Hui Lin , Ulf-G. Meißner

We review the experimental and theoretical status of elastic electron scattering and elastic low-energy photon scattering (with both real and virtual photons) from the nucleon. As a consequence of new experimental facilities and new…

Nuclear Experiment · Physics 2008-11-26 Charles Earl Hyde-Wright , Kees de Jager

We apply a subtracted dispersion relation (DR) formalism with the aim to improve predictions for the two-photon exchange (TPE) corrections to elastic electron-proton scattering observables at small momentum transfers. We study the formalism…

High Energy Physics - Phenomenology · Physics 2016-02-01 O. Tomalak

The structure function approach and the parton picture, developed for the theoretical description of the deep inelastic electron-proton scattering, also proved to be very effective for calculation of radiative corrections in Quantum…

High Energy Physics - Phenomenology · Physics 2020-09-28 V. S. Fadin , R. E. Gerasimov

Multi-photon exchange contributions are important in extracting the proton charge radius from elastic electron--proton scattering. So far, only diagrams associated with the exchange of a second photon have been evaluated. At the very low…

Nuclear Experiment · Physics 2013-09-10 John Arrington

The effects of two-photon exchange corrections, suggested to explain the difference between measurements of the proton elastic electromagnetic form factors using the polarization transfer and Rosenbluth techniques, have been studied in…

Nuclear Experiment · Physics 2014-11-18 V. Tvaskis , J. Arrington , M. E. Christy , R. Ent , C. E. Keppel , Y. Liang , G. Vittorini

We calculate contributions of hadron resonances to two-photon exchange effects in electron-proton scattering. In addition to the nucleon and P33 resonance, the following heavier resonances are included as intermediate states in the…

Nuclear Theory · Physics 2008-11-26 S. Kondratyuk , P. G. Blunden

Precisely measured electron-proton elastic scattering cross sections [Phys. Rev. Lett. {\bf 105}, 242002 (2010)] are reanalyzed to evaluate their strength for determining the rms charge radius ($R_{\rm E}$) of the proton. More than half of…

Nuclear Experiment · Physics 2016-03-23 M. Horbatsch , E. A. Hessels

We calculate the two-photon exchange (TPE) corrections in the region where the kinematical variables describing the elastic $ep$ scattering are moderately large momentum scales relative to the soft hadronic scale. For such kinematics we use…

High Energy Physics - Phenomenology · Physics 2015-06-12 N. Kivel , M. Vanderhaeghen

QED radiative corrections to elastic electron-proton scattering at low energies are discussed. Corrections to the electron line and effects due to vacuum polarization are computed. Higher order effects are estimated for the conditions of…

High Energy Physics - Phenomenology · Physics 2017-08-11 A. B. Arbuzov , T. V. Kopylova

Significant discrepancies have been observed between proton form factors as measured by Rosenbluth separation and polarization transfer techniques. There are indications that this difference may be caused by corrections to the one photon…

High Energy Physics - Phenomenology · Physics 2009-11-10 J. Arrington