J. Mei

TL;DR: The Qweak experiment has measured the parity-violating asymmetry in polarized e-p elastic scattering at Q2 = 0.025(GeV/c)2, employing 145 microamps of 89% longitudinally polarized electrons on a 34.4cm long liquid hydrogen target at Jefferson Lab.

TL;DR: In this paper, the weak charge of the proton was measured using parity-violating (PV) polarized electron-proton scattering asymmetry, and the value of Q_W^p was derived from the predicted neutral electroweak force.

TL;DR: The results show that precision parity-violating measurements enable searches for physics beyond the standard model that can compete with direct searches at high-energy accelerators and, together with astronomical observations, can provide fertile approaches to probing higher mass scales.

TL;DR: The Jefferson Lab weak experiment determined the weak charge of the proton by measuring the parity-violating elastic scattering asymmetry of longitudinally polarized electrons from an unpolarized liquid hydrogen target at small momentum transfer as discussed by the authors.

TL;DR: A 2% precision measurement of the beam-normal single-spin asymmetry in elastic electron-proton scattering with a mean scattering angle of θ_{lab}=7.9° provides a stringent test of two-photon exchange models at far-forward scattering angles where they should be most reliable.