Speaker
Joshua Hoskins
(College of William and Mary)
Description
The Qweak experiment at Jefferson Laboratory will provide a 4% measurement of the proton's weak charge Q_w^p, using parity-violating electron scattering from Hydrogen at low momentum transfer. The experiment will measure a tiny parity-violating asymmetry ~256 parts per billion, which means control and precise measurement of systematic errors is a must. While great care is being taken to suppress or eliminate helicity-correlated changes in electron beam properties at the source, broken symmetries in the experimental apparatus can produce false asymmetries in the detected signal. For Qweak we measure the detector sensitivities dA/dx_i (i = 1..5) for first order offline correction of beam-related false asymmetries, using both regression against natural beam motion and a driven modulation system. I will discuss the methodology and status of the helicity-correlated detector sensitivities and how they relate to a precision measurement Qweak.
