Effect of two-boson exchange on parity-violating e-p scattering

Abstract

We compute the corrections from two-photon and photon-Z exchange in parity-violating elastic electron-proton scattering, used to extract the strange form factors of the proton. We use a hadronic formalism that successfully reconciled the earlier discrepancy in the proton's electron to magnetic form factor ratio, suitably extended to the weak sector. Implementing realistic electroweak form factors, we find effects of the order 2-3% at Q^2 < 0.1 GeV^2, which are largest at backward angles, and have a strong Q^2 dependence at low Q^2. Two-boson contributions to the weak axial current are found to be enhanced at low Q^2 and for forward angles. We provide corrections at kinematics relevant for recent and upcoming parity-violating experiments.

10 pages, 3 figures, 1 table, published version

References in corpus (4)

• Global analysis of proton elastic form factor data with two-photon exchange corrections
• Precision Measurements of the Nucleon Strange Form Factors at Q^2 ~0.1 GeV^2
• Extracting nucleon strange and anapole form factors from world data
• The Two-Photon-Exchange and γZ-Exchange Corrections to parity-Violating Elastic Electron-Proton Scattering

Cited by in corpus (13)

• Review of two-photon exchange in electron scattering
• Two-photon exchange in elastic electron-proton scattering
• gamma-Z corrections to forward-angle parity-violating e-p scattering
• A dispersive approach to two-photon exchange in elastic electron-proton scattering
• New formulation of gamma-Z box corrections to the weak charge of the proton
• Gamma-Z box contributions to parity violating elastic e-p scattering
• Detailed analysis of two-boson exchange in parity-violating e-p scattering
• On the two-boson exchange corrections to parity-violating elastic electron-proton scattering
• Form factors and other measures of strangeness in the nucleon
• Contribution of Two-Boson-Exchange with $\Delta (1232)$ Excitation to Parity-Violating Elastic Electron-Proton Scattering
• Strange Vector Form Factors from Parity-Violating Electron Scattering
• Two-Boson Exchange Physics: A Brief Review
• Two-Photon Exchange in Electron-Proton Elastic Scattering: Theory Update