Two-photon exchange corrections to elastic $e^{-}$-proton scattering: Full dispersive treatment of $\pi N$ states at low momentum transfers

Abstract

We evaluate the pion-nucleon intermediate-state contribution to the two-photon exchange (TPE) correction in the elastic electron-nucleon scattering within a dispersive framework. We calculate the contribution from all $\pi N$ partial waves using the MAID parametrization. We provide the corresponding TPE correction to the unpolarized $ep$ scattering cross section in the region of low momentum transfer $Q^2\lesssim 0.064{\mathrm{GeV}}^2$, where no analytical continuation into the unphysical region of the TPE scattering amplitudes is required. We compare our result in the forward angular region with an alternative TPE calculation, in terms of structure functions, and find a good agreement, indicating a small contribution at low $Q^2$ due to discontinuities beyond $\pi N$. We also compare our results with empirical fits.

34 pages, 14 figures, version published in Phys. Rev. D 95, 096001 (2017)

References in corpus (23)

• Unitary Isobar Model - MAID2007
• High-precision determination of the electric and magnetic form factors of the proton
• Electromagnetic excitation of the Delta(1232)-resonance
• The Proton Radius Puzzle
• Two-Photon Physics in Hadronic Processes
• Theoretical Constraints and Systematic Effects in the Determination of the Proton Form Factors
• Proton polarisability contribution to the Lamb shift in muonic hydrogen at fourth order in chiral perturbation theory
• Measurement of the two-photon exchange contribution to the elastic $e^{\pm }p$ scattering cross sections at the VEPP-3 storage ring
• Towards a resolution of the proton form factor problem: new electron and positron scattering data
• Search for effects beyond the Born approximation in polarization transfer observables in $\vec{e}p$ elastic scattering
• Hard Two-Photon Contribution to Elastic Lepton-Proton Scattering: Determined by the OLYMPUS Experiment
• Two-photon exchange in dispersion approach
• The NRQED lagrangian at order 1/M^4
• Two-photon exchange in elastic electron-proton scattering : QCD factorization approach
• The two-photon exchange contribution to muonic hydrogen from chiral perturbation theory
• Contribution of spin 1/2 and 3/2 resonances to two-photon exchange effects in elastic electron-proton scattering
• Forward virtual Compton scattering and the Lamb shift in chiral perturbation theory
• Perturbative QCD predictions for two-photon exchange
• On Delta resonance contribution to two-photon exchange amplitude
• Dispersive contributions to $e^{+}p/e^{-}p$ cross section ratio in forward regime
• Transverse Beam Spin Asymmetries at Backward Angles in Elastic Electron-Proton and Quasi-elastic Electron-Deuteron Scattering
• Forward sum rule for the $2\gamma$-exchange correction to the charge radius extraction from elastic electron scattering
• Invariant Amplitudes for Pion Electroproduction

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• Review of experimental and theoretical status of the proton radius puzzle
• Two-photon exchange correction to the hyperfine splitting in muonic hydrogen
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