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Measurement of the Neutral Weak Form Factors of the Proton

HAPPEX Collaboration·K. A. Aniol
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Abstract

We have measured the parity-violating electroweak asymmetry in the elastic scattering of polarized electrons from the proton. The kinematic point (theta_lab = 12.3 degrees and Q^2=0.48 (GeV/c)^2) is chosen to provide sensitivity, at a level that is of theoretical interest, to the strange electric form factor G_E^s. The result, A=-14.5 +- 2.2 ppm, is consistent with the electroweak Standard Model and no additional contributions from strange quarks. In particular, the measurement implies G_E^s + 0.39G_M^s = 0.023 +- 0.034 (stat) +- 0.022 (syst) +- 0.026 (delta G_E^n), where the last uncertainty arises from the estimated uncertainty in the neutron electric form factor.

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HAPPEX Collaboration, K. A. Aniol. 1998-10-16. Measurement of the Neutral Weak Form Factors of the Proton. https://doi.org/10.1103/physrevlett.82.1096

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