相关论文: Precision Measurement of the Beam-Normal Single-Sp…
This is a short review of the physics of single-spin asymmetries caused by two-photon exchange in elastic scattering of electrons by nucleons and nuclei.
The ratio of the proton's electric to magnetic form factor, G_E/G_M, can be extracted in elastic electron-proton scattering by measuring either cross sections, beam-target asymmetry or recoil polarization. Separate determinations of G_E/G_M…
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 report a new measurement of the parity-violating asymmetry in elastic electron scattering from the proton at backward scattering angles. This asymmetry is sensitive to the strange magnetic form factor of the proton as well as electroweak…
We report on the status of the Novosibirsk experiment on a precision measurement of the ratio $R$ of the elastic $e^+ p$ and $e^- p$ scattering cross sections. Such measurements determine the two-photon exchange effect in elastic…
Elastic lepton scattering off of a nucleon has proved to be an efficient tool to study the structure of the hadron. Modern cross section and asymmetry measurements at Jefferson Lab require effects beyond the leading order Born approximation…
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…
Compton scattering by the proton has been measured over a wide range covering photon energies 250 MeV < E_\gamma < 800 MeV and photon scattering angles 30^0 < \theta^{lab}_\gamma < 150^0, using the tagged-photon facility at MAMI (Mainz) and…
We calculate the two-boson-exchange (TBE) corrections to the parity-violating asymmetry of the elastic electron-proton scattering in a simple hadronic model including the nucleon and the $\Delta(1232)$ intermediate states. We find that…
Modern experiments with heavy ion-leptons collisions open the possibility to measure the deviation of cross section of small angles electron(positron)-ion elastic scattering from the Rutherford formula due to multiple virtual photons…
The beam asymmetry, $\Sigma$, was measured at ELSA in the reaction $\vec \gamma p \to \eta p$ using linearly polarised tagged photon beams, produced by coherent bremsstrahlung off a diamond. The crystal was oriented to provide polarised…
Exclusive electroproduction of pi+ mesons was studied by scattering 27.6 GeV positrons or electrons off a transversely polarized hydrogen target. The single-spin azimuthal asymmetry with respect to target polarization was measured as a…
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…
The beam normal spin asymmetry for the elastic $eN$ scattering is studied in the leading logarithm approximation. We derive the expression for the asymmetry, which is valid for any scattering angles. The result is compared with the results…
A single-spin asymmetry in the azimuthal distribution of neutral pions relative to the lepton scattering plane has been measured for the first time in deep-inelastic scattering of positrons off longitudinally polarized protons. The…
Using the relativistic Eikonal approximation, we study the one and two photon exchange amplitudes in elastic electron-nucleon scattering for the case of transversely polarized nucleons with unpolarized electrons beam. In our approach, we…
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 physics scope of a possible future experiment utilizing an internal polarized nucleon target in the HERA proton beam is discussed. By measuring single spin asymmetries in inclusive particle production at 820~GeV beam energy the…
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…
Cross sections for elastic Compton scattering from the deuteron were measured over the laboratory angles 35-150 deg. Tagged photons in the laboratory energy range 84-105 MeV were scattered from liquid deuterium and detected in the…