Related papers: Two-Photon Exchange and Electromagnetic Proton For…
We examine the two-photon exchange corrections to elastic electron-proton scattering within a dispersive approach, including contributions from both Nucleon and Delta intermediate states. The dispersive analysis avoids off-shell…
The proton elastic form factor ratio is accessible in unpolarized Rosenbluth-type experiments as well as experiments which make use of polarization degrees of freedom. The extracted values show a distinct discrepancy, growing with $Q^2$.…
We estimate the two-photon exchange contribution to elastic electron-proton scattering at large momentum transfer $Q^2$. It is shown that the leading two-photon exchange amplitude behaves as $1/Q^4$ relative to the one-photon amplitude, and…
We address the discrepancy between the Rosenbluth and polarization transfer data for the electromagnetic form factors of the nucleon. Assuming that the effect of two-photon corrections on the polarization transfer data is negligible, we…
World data on the lepton-charge asymmetry in the elastic and inelastic lepton scattering off the proton and nuclei are compiled and discussed. After reviewing the published results, we compare the elastic data to a model calculation of the…
We extract the two-photon exchange (TPE) contributions to electron--proton elastic scattering using two parametrizations and compare the results to different phenomenological extractions and direct calculations of the TPE effects. We find…
Two-photon exchange contributions to elastic electron-scattering are reviewed. The apparent discrepancy in the extraction of elastic nucleon form factors between unpolarized Rosenbluth and polarization transfer experiments is discussed, as…
We present new precision measurements of the elastic electron-proton scattering cross section for momentum transfer (Q$^2$) up to 15.75~\gevsq. Combined with existing data, these provide an improved extraction of the proton magnetic form…
Current status of the two-boson exchange contributions to elastic electron-proton scattering, both for parity conserving and parity-violating, is briefly reviewed. How the discrepancy in the extraction of elastic nucleon form factors…
We review recent theoretical and experimental progress on the role of two-photon exchange (TPE) in electron-proton scattering at low to moderate momentum transfers. We make a detailed comparison and analysis of the results of competing…
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…
We extend the general formalism of two-photon exchange to elastic lepton-nucleon scattering by accounting for all lepton mass terms. We then perform a numerical estimate of the muon-proton scattering at low momentum transfer in view of the…
We propose possible methods to measure the nucleon electromagnetic form factors in presence of two-photon exchange. Using a general parametrization of the spin structure of the matrix element for elastic $eN$-scattering, in terms of three…
We discuss effects of two-photon exchange (TPE) in various observables of the elastic ep-scattering. The imaginary part of the TPE amplitude manifests in target and beam normal spin asymmetries. The real part contributes to the…
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…
It has been suggested that two-photon exchange corrections could explain the discrepancy between Rosenbluth extractions of the proton form factors and recent polarization transfer measurements. We propose a precise comparison of…
We present the dispersion relation approach based on unitarity and analyticity to evaluate the two-photon exchange contribution to elastic electron-proton scattering. The leading elastic and first inelastic $\pi N$ intermediate state…
We calculate two-photon exchange amplitude for the elastic electron-proton scattering in the framework of dispersion relations. The imaginary part of the amplitude is determined by unitarity. Since in the unitarity relation intermediate…
We calculate two-photon exchange amplitude for the elastic electron-pion scattering in the dispersion-relation inspired approach, including both elastic and inelastic contributions. The latter was modelled as a sum of \rho and b_1(1235)…
We calculate the two-photon exchange corrections to electron-proton scattering with nucleon and $\Delta$ intermediate states. The results show a dependence on the elastic nucleon and nucleon-$\Delta$-transition form factors used as input…