Article

# New Measurement of Parity Violation in Elastic Electron-Proton Scattering and Implications for Strange Form Factors

06/2000; DOI:doi:10.1016/S0370-2693(01)00446-4
Source: arXiv

ABSTRACT We have measured the parity-violating electroweak asymmetry in the elastic scattering of polarized electrons from the proton. The result is A = -15.05 +- 0.98(stat) +- 0.56(syst) ppm at the kinematic point theta_lab = 12.3 degrees and Q^2 = 0.477 (GeV/c)^2. The measurement implies that the value for the strange form factor (G_E^s + 0.392 G_M^s) = 0.025 +- 0.020 +- 0.014, where the first error is experimental and the second arises from the uncertainties in electromagnetic form factors. This measurement is the first fixed-target parity violation experiment that used either a strained' GaAs photocathode to produce highly polarized electrons or a Compton polarimeter to continuously monitor the electron beam polarization. Comment: 8 pages, 4 figures, Tex, elsart.cls; revised version as accepted for Phys. Lett. B

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14 Feb 2013

### Keywords

4 figures

strained' GaAs photocathode

Compton polarimeter

electromagnetic form factors

electron beam polarization

first fixed-target parity violation experiment

kinematic point theta_lab

parity-violating electroweak asymmetry

polarized electrons

strange form factor

uncertainties