Qweak Apparatus

QWEAK Experiment

The Qweak experiment at Jefferson Lab is making the first direct measurement of the weak charge of the proton, $Q^p_W$. This quantity is suppressed in the SM making a good candidate for search for new physics beyond the SM at the TeV scale. Operationally, we measure a small (about $ -0.200 ppm $) parity-violating asymmetry in elastic electron-proton scattering in integrating mode while flipping the helicity of the electrons 1000 times per second. Commissioning took place Fall 2010, and we finished taking data in early summer 2012. The first results based on small sub set of data are a proof of principle of the Qweak data analysis and we are getting ready to for obtaining full results.

QWEAK inital results and NIM paper