Abstract
In May 2012, the \(Q^{p}_{\rm Weak}\) collaboration completed a two year measurement program to determine the weak charge of the proton \({Q^{p}_W} = ( 1 - 4\sin^2{\theta_{W}})\) at the Thomas Jefferson National Accelerator Facility (TJNAF). The experiment was designed to produce a 4.0 % measurement of the weak charge, via a 2.5 % measurement of the parity violating asymmetry in the number of elastically scattered 1.165 GeV electrons from protons, at forward angles. At the proposed precision, the experiment would produce a 0.3 % measurement of the weak mixing angle at a momentum transfer of Q 2 = 0.026 GeV2, making it the most precise stand alone measurement of the weak mixing angle at low momentum transfer. In combination with other parity measurements, \(Q^{p}_{\rm Weak}\) will also provide a high precision determination of the weak charges of the up and down quarks. At the proposed precision, a significant deviation from the Standard Model prediction could be a signal of new physics at mass scales up to ≃ 6 TeV, whereas agreement would place new and significant constraints on possible Standard Model extensions at mass scales up to ≃ 2 TeV. This paper provides an overview of the physics and the experiment, as well as a brief look at some preliminary diagnostic and analysis data.
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J. M. Finn deceased.
The 5th international symposium on Symmetries in Subatomic Physics (SSP 2012), Groningen, The Netherlands, 18–22 June 2012.
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Androic, D., Armstrong, D.S., Asaturyan, A. et al. The \({Q^{p}_{\rm Weak}}\) experiment. Hyperfine Interact 214, 21–30 (2013). https://doi.org/10.1007/s10751-013-0782-0
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DOI: https://doi.org/10.1007/s10751-013-0782-0