Related papers: The Q_weak Experimental Apparatus
We have performed a novel comparison between electron-beam polarimeters based on M{\o}ller and Compton scattering. A sequence of electron-beam polarization measurements were performed at low beam currents ($<$ 5 $\mu$A) during the $Q_{\rm…
The Spin Asymmetries of the Nucleon Experiment (SANE) performed inclusive, double-polarized electron scattering measurements of the proton at the Continuous Electron Beam Accelerator Facility at Jefferson Lab. A novel detector array…
We have measured the parity-violating electroweak asymmetry in the elastic scattering of polarized electrons from the proton. The kinematic point (theta_lab = 12.3 degrees and Q^2=0.48 (GeV/c)^2) is chosen to provide sensitivity, at a level…
We have measured the parity-violating electroweak asymmetry in the elastic scattering of polarized electrons from the proton. The result is A = -15.05 +- 0.98(stat) +- 0.56(syst) ppm at the kinematic point theta_lab = 12.3 degrees and Q^2 =…
We report on precision measurements of the elastic cross section for electron-proton scattering performed in Hall C at Jefferson Lab. The measurements were made at 28 unique kinematic settings covering a range in momentum transfer of 0.4…
Measurement of the parity-violating electron scattering asymmetry from ${}^{208}$Pb has demonstrated a new opportunity at Jefferson Lab to measure the weak charge distribution and hence pin down the neutron radius in nuclei in a relatively…
We report measurements of the parity-conserving beam-normal single-spin elastic scattering asymmetries $B_n$ on $^{12}$C and $^{27}$Al, obtained with an electron beam polarized transverse to its momentum direction. These measurements add an…
The physics case and an experimental overview of the MOLLER (Measurement Of a Lepton Lepton Electroweak Reaction) experiment at the 12 GeV upgraded Jefferson Lab are presented. A highlight of the Fundamental Symmetries subfield of the 2007…
High quality polarized electron beams at Jefferson Lab make possible precision measurements of hadronic properties in the regime of strongly interacting QCD. We will describe a few programs at Jefferson Lab that are making measurements that…
Measurement of the parity-violating electron scattering asymmetry is an established technique at Jefferson Lab and provides a new opportunity to measure the weak charge distribution and hence pin down the neutron radius in nuclei in a…
A Compton polarimeter has been installed in Hall A at Jefferson Laboratory. This letter reports on the first electron beam polarization measurements performed during the HAPPEX experiment at an electron energy of 3.3 GeV and an average…
Precise measurements of the proton electromagnetic form factor ratio $R = \mu_p G_E^p/G_M^p$ using the polarization transfer method at Jefferson Lab have revolutionized the understanding of nucleon structure by revealing the strong decrease…
We report results for the virtual photon asymmetry $A_1$ on the nucleon from new Jefferson Lab measurements. The experiment, which used the CEBAF Large Acceptance Spectrometer and longitudinally polarized proton ($^{15}$NH$_3$) and deuteron…
The ratio of the proton form factors, GEp/GMp, has been measured from Q2 of 0.5 GeV2 to 8.5 GeV2, at the Jefferson Laboratory, using the polarization transfer method. This ratio is extracted directly from the measured ratio of the…
We have measured the parity-violating electroweak asymmetry in the elastic scattering of polarized electrons from protons. Significant contributions to this asymmetry could arise from the contributions of strange form factors in the…
As part of the spin physics program at Jefferson Laboratory (JLab), a M\o ller polarimeter was developed to measure the polarization of electron beam of energies 0.8 to 5.0 GeV. A unique signature for M\o ller scattering is obtained using a…
We describe the current status of the DarkLight experiment at Jefferson Laboratory. DarkLight is motivated by the possibility that a dark photon in the mass range 10 to 100 MeV/c$^2$ could couple the dark sector to the Standard Model.…
We analyze the dispersion correction to elastic parity violating electron-proton scattering due to $\gamma Z$ exchange. In particular, we explore the theoretical uncertainties associated with modeling contributions of hadronic intermediate…
This article describes the future P2 parity-violating electron scattering facility at the upcoming MESA accelerator in Mainz. The physics program of the facility comprises indirect, high precision search for physics beyond the Standard…
Low-energy neutral-current couplings arising in the Standard Model of electroweak interactions can be constrained in lepton scattering off hydrogen or a nuclear fixed target. Recent polarized electron scattering experiments at Jefferson Lab…