Measurement of the strange quark contribution to the magnetic moment of the proton.

摘要

We report the first measurement of the parity-violating asymmetry in elastic electron scattering from the proton. The experiment was performed at the MIT/Bates Linear Accelerator Center using a 200 MeV beam of longitudinally polarized electrons incident on a 40 cm long liquid hydrogen target. The scattered electrons are detected in a large acceptance (1.44 sr) air Cerenkov detector. The detector covers an angular range of ;We present a detailed account of the analysis performed on the first two high statistics data runs for the SAMPLE experiment. Our result for the asymmetry, representing 35 Coulombs of collected charge, is (