Results from the bates 12C parity experiment

We report the results of an experiment measuring the the parity-violating electroweak asymmetry in the elastic scattering of polarized electrons from 12 C nuclei. We obtain A exp = 0.60 ± 0.14 ± 0.02 ppm. The first error is statistical and the second is systematic. Using our measured beam polarization of 0.37 ± 0.02, we compute the isoscalar vector hadronic coupling constant γ to be 0.136 ± 0.032 ± 0.009. This agrees with the tree level Standard Model prediction of γ = 0.155 .