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 ${\hat{I}}^{3}Z$ interference structure functions $F_1^{{\hat{I}}^{3}Z}$ and $F_2^{{\hat{I}}^{3}Z}$ used in those calculations, which are also used for determination of the two-boson exchange box diagram (${\square }_{{\hat{I}}^{3}Z}$) contribution to parity-violating elastic scattering measurements. A positive parity-violating asymmetry for inclusive $\ddot{I}{€}^{-}$ 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 $\ddot{I}{€}^{-}$ production.

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