The Q<sub>weak </sub>experiment measured a parity violating asymmetry of longitudally polarized electrons scattered off an unpolarized liquid hydrogen target, which enabled the determination of the weak charge of the proton. The largest source of background uncertainity comes from the aluminium casing of the liquid hydrogen target; instead of scattering off the liquid hydrogen, a fraction of the polarized electrons scattered off the aluminium casing surrounding the liquid hydrogen. In order to obtain a more accurate measurement of the weak charge of the proton, the background signal fraction due to scattering off the aluminum casing must be removed from the data. A new approach to this correction is proposed here, which uses the rates from the target when it was filled with a low density hydrogen gas and then scaled up to the rate of the liquid hydrogen target. While this method of determining the aluminium background signal fraction introduces a new error into the calculation--the uncertainity in the density of the hydrogen gas--it removes errors which were present in previous calculations of the background signal fraction, leading to an overall lower error.

Determination of aluminium background signal fraction in the Q<sub>weak</sub> experiment

253rd National Meeting (2017)

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Determination of aluminium background signal fraction in the Qweak experiment

Determination of aluminium background signal fraction in the Q_weak experiment