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Full-Text Articles in Physics
Precision Measurement Of The Beam-Normal Single-Spin Asymmetry In Forward-Angle Elastic Electron-Proton Scattering, D. Androic, David S. Armstrong, Et Al.
Precision Measurement Of The Beam-Normal Single-Spin Asymmetry In Forward-Angle Elastic Electron-Proton Scattering, D. Androic, David S. Armstrong, Et Al.
Arts & Sciences Articles
A beam-normal single-spin asymmetry generated in the scattering of transversely polarized electrons from unpolarized nucleons is an observable related to the imaginary part of the two-photon exchange process. We report a 2% precision measurement of the beam-normal single-spin asymmetry in elastic electron-proton scattering with a mean scattering angle of theta_lab = 7.9 degrees and a mean energy of 1.149 GeV. The asymmetry result is B_n = -5.194 +- 0.067 (stat) +- 0.082 (syst) ppm. This is the most precise measurement of this quantity available to date and therefore provides a stringent test of two-photon exchange models at far-forward scattering angles …
Demonstration Of The Lateral Ac Skin Effect Using A Pickup Coil, Anne E. Blackwell, Andrew P. Rotunno, Seth Aubin
Demonstration Of The Lateral Ac Skin Effect Using A Pickup Coil, Anne E. Blackwell, Andrew P. Rotunno, Seth Aubin
Arts & Sciences Articles
We present a simple demonstration of the skin effect by observing the current distribution in a wide rectangular strip conductor driven at frequencies in the 0.25–5 kHz range. We measure the amplitude and phase of the current distribution as a function of the transverse position and find that they agree well with numerical simulations: The current hugs the edges of the strip conductor with a significant variation in phase across the width. The experimental setup is simple, uses standard undergraduate physics instructional laboratory equipment, and is easy to implement as a short in-class demonstration. Our study is motivated by modeling …
Measurement Of The 3he Spin-Structure Functions And Of Neutron (3he) Spin-Dependent Sum Rules At 0.035 ≤ Q2 ≤ 0.24 Gev2, Jefferson Lab E97-110 Collaboration, David S. Armstrong
Measurement Of The 3he Spin-Structure Functions And Of Neutron (3he) Spin-Dependent Sum Rules At 0.035 ≤ Q2 ≤ 0.24 Gev2, Jefferson Lab E97-110 Collaboration, David S. Armstrong
Arts & Sciences Articles
The spin-structure functions g1 and g2, and the spin-dependent partial cross-section σTT have been extracted from the polarized cross-sections differences, σ| ν, Q 2 and σ⊥ ν, Q 2 measured for the 3 > He(e>, e' )X reaction, in the E97-110 experiment at Jefferson Lab. Polarized electrons with energies from 1.147 to 4.404 GeV were scattered at angles of 6◦ and 9◦ from a longitudinally or transversely polarized 3He target. The data cover the kinematic regions of the quasi-elastic, resonance production and beyond. From the extracted spin-structure functions, the first moments 1 (Q2) , 2 (Q2) and ITT Q 2 …
Parity-Violating Inelastic Electron-Proton Scattering At Low Q^2 Above The Resonance Region, D. Androic, David S. Armstrong, Qweak Collaboration
Parity-Violating Inelastic Electron-Proton Scattering At Low Q^2 Above The Resonance Region, D. Androic, David S. Armstrong, Qweak Collaboration
Arts & Sciences Articles
We report the measurement of the parity-violating asymmetry for the inelastic scattering of electrons from the proton, at Q2=0.082GeV2 and W=2.23 GeV, above the resonance region. The result AInel=−13.5±2.0(stat)±3.9(syst) ppm agrees with theoretical calculations, and helps to validate the modeling of the γZ interference structure functions FγZ1 and FγZ2 used in those calculations, which are also used for determination of the two-boson exchange γ−Z box diagram (□γZ) contribution to parity-violating elastic scattering measurements. A positive parity-violating asymmetry for inclusive π− production was observed, as well as positive beam-normal single-spin asymmetry for scattered electrons and a negative beam-normal single-spin asymmetry for …