Measurement of the Strange Quark Contribution to Nucleon Structure Through Parity-Violating Electron Scattering

Abstract

The G0 backward angle experiment, completed in Hall C of the Thomas Jefferson National Accelerator Facility (TJNAF), measured parity-violating asymmetries

in elastic electron-proton and quasielastic electron-deuteron scattering at Q<super>2</super> = 0.22 and 0.63 (GeV/c)<super>2</super> . The asymmetries are sensitive to strange quark contributions to currents in the nucleon and the nucleon axial-vector current. The results indicate strange quark contributions of < 10% of the charge and magnetic nucleon form factors at these four-momentum transfers. This was also the first measurement of the anapole moment effects in the axial-vector current at these four-momentum transfers.