Parity-Violating Inelastic Electron-Proton Scattering at Low $Q^2$ Above the Resonance Region

Abstract

We report the measurement of the parity-violating asymmetry for the inelastic scattering of electrons from the proton, at $Q^2=0.082$ GeV${}^2$ and $W=2.23$ GeV, above the resonance region. The result $A_{\mathrm{Inel}}=-13.5\pm 2.0(\mathrm{stat})\pm 3.9(\mathrm{syst})$~ppm agrees with theoretical calculations, and helps to validate the modeling of the $\gamma Z$ interference structure functions $F_1^{\gamma Z}$ and $F_2^{\gamma Z}$ used in those calculations, which are also used for determination of the two-boson exchange box diagram (${\square }_{\gamma Z}$) contribution to parity-violating elastic scattering measurements. A positive parity-violating asymmetry for inclusive ${\pi }^{-}$ production was observed, as well as positive beam-normal single-spin asymmetry for scattered electrons and a negative beam-normal single-spin asymmetry for inclusive ${\pi }^{-}$ production.

18 pages, 9 figures, version accepted in Physical Review C

References in corpus (12)

• Precision Measurement of the Weak Charge of the Proton
• Two-Photon Physics in Hadronic Processes
• Measurement of the two-photon exchange contribution to the elastic $e^{\pm }p$ scattering cross sections at the VEPP-3 storage ring
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• Gamma-Z box contributions to parity violating elastic e-p scattering
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• Transverse Beam Spin Asymmetries at Backward Angles in Elastic Electron-Proton and Quasi-elastic Electron-Deuteron Scattering
• Toward a First-Principles Calculation of Electroweak Box Diagrams
• Beam normal spin asymmetry for the $ep\to e\Delta (1232)$ process
• A novel comparison of Møller and Compton electron-beam polarimeters
• Reduced uncertainty of the axial $\gamma Z$-box correction to the proton's weak charge

Cited by in corpus (2)

• The Standard Model theory of neutron beta decay
• Electroweak Nuclear Properties from Single Molecular Ions in a Penning Trap