Collinear Photon Exchange in the Beam Normal Polarization Asymmetry of Elastic Electron-Proton Scattering

Abstract

The parity-conserving single-spin beam asymmetry of elastic electron-proton scattering is induced by an absorptive part of the two-photon exchange amplitude. We demonstrate that this asymmetry has logarithmic and double-logarithmic enhancement due to contributions of hard collinear quasi-real photons. An optical theorem is used to evaluate the asymmetry in terms of the total photoproduction cross section on the proton, predicting its magnitude at a few parts per million for high electon beam energies and small scattering angles. At fixed 4-momentum transfers, the asymmetry is rising logarithmically with increasing electron beam energy, following the high-energy diffractive behavior of total photoproduction cross section on the proton.

6 pages, 5 figures, Corrected an algebraic error in Eq.(17), other formulas and plots changed accordingly

Cited by in corpus (28)

• The two-photon exchange contribution to elastic electron-nucleon scattering at large momentum transfer
• Two-Photon Physics in Hadronic Processes
• Two-photon exchange in elastic electron-proton scattering
• Model-dependence of the $\gamma Z$ dispersion correction to the parity-violating asymmetry in elastic $ep$ scattering
• New Measurements of the Transverse Beam Asymmetry for Elastic Electron Scattering from Selected Nuclei
• Transverse target spin asymmetry in inclusive DIS with two-photon exchange
• Transverse Beam Spin Asymmetries in Forward-Angle Elastic Electron-Proton Scattering
• Analyzing power in elastic scattering of the electrons off a spin-0 target
• Dispersive contributions to $e^{+}p/e^{-}p$ cross section ratio in forward regime
• Transverse single spin asymmetries in inclusive deep-inelastic scattering
• New Measurements of the Beam-Normal Single Spin Asymmetry in Elastic Electron Scattering Over a Range of Spin-0 Nuclei
• Beam normal spin asymmetry in the quasi-RCS approximation
• Single--Spin Asymmetries in the Bethe--Heitler Process $e^{-}+p\to e^{-}+\gamma +p$ from QED Radiative Corrections
• Doubly virtual Compton scattering and the beam normal spin asymmetry
• Target-normal single-spin asymmetry in elastic electron-nucleon scattering
• Beam-Normal Single Spin Asymmetry in Elastic Electron Scattering off ${}^{28}$Si and ${}^{90}$Zr
• Beam-normal single-spin asymmetry in elastic scattering of electrons from a spin-0 nucleus
• Beam normal spin asymmetry of elastic $eN$ scattering in the leading logarithm approximation
• Precision Measurement of the Beam-Normal Single-Spin Asymmetry in Forward-Angle Elastic Electron-Proton Scattering
• Measurement of the Beam-Normal Single-Spin Asymmetry for Elastic Electron Scattering from ${}^{12}$C and ${}^{27}$Al
• Single spin asymmetries in elastic electron-nucleon scattering
• Two photon exchange in elastic electron scattering off hadronic systems
• Lepton mass effects for beam-normal single-spin asymmetry in elastic muon-proton scattering
• Target normal single-spin asymmetry in inclusive electron-nucleon scattering with two-photon exchange: Analysis using $1/N_c$ expansion
• Two-Photon Exchange in Electron-Proton Elastic Scattering: Theory Update
• Dispersion effects in elastic electron scattering from ${}^{208}$Pb
• Target normal single-spin asymmetry in inclusive electron-nucleon scattering in the 1/Nc expansion
• Charge and spin asymmetries in elastic lepton-nucleon scattering