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arXiv · 0705.1525

Transverse Beam Spin Asymmetries in Forward-Angle Elastic Electron-Proton Scattering

G0 Collaboration·D. S. Armstrong
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Abstract

We have measured the beam-normal single-spin asymmetry in elastic scattering of transversely-polarized 3 GeV electrons from unpolarized protons at Q^2 = 0.15, 0.25 (GeV/c)^2. The results are inconsistent with calculations solely using the elastic nucleon intermediate state, and generally agree with calculations with significant inelastic hadronic intermediate state contributions. A_n provides a direct probe of the imaginary component of the 2-gamma exchange amplitude, the complete description of which is important in the interpretation of data from precision electron-scattering experiments.

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G0 Collaboration, D. S. Armstrong. 2007-07-10. Transverse Beam Spin Asymmetries in Forward-Angle Elastic Electron-Proton Scattering. https://doi.org/10.1103/physrevlett.99.092301

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