Dr. Emlyn W. Hughes
California Institute of
Technology
Title: Parity Violation in Electron Scattering
Low-energy precision
measurements of fundamental parameters in the electroweak theory provide
information on new physics at high mass scales, beyond the reach of present-day
colliders. We report on a
first measurement of the electroweak mixing angle from the observation of a
parity-violating asymmetry in the scattering of high energy polarized electrons
by unpolarized electrons in a liquid
hydrogen target. The parity-violating asymmetry is very small, on the order of
100 parts per billion. The experiment was performed in the fixed target program
at the Stanford Linear Accelerator Center. We also compare the results to other
low energy test of the electroweak theory and summarize the status of this
field of study. The present experiment gives sensitivity to new physics at
the TeV energy scale.
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