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Two-photon exchange and elastic electron-proton scattering

P. G. Blunden·W. Melnitchouk·J. A. Tjon
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Abstract

Two-photon exchange contributions to elastic electron-proton scattering cross sections are evaluated in a simple hadronic model including the finite size of the proton. The corrections are found to be small in magnitude, but with a strong angular dependence at fixed $Q^2$. This is significant for the Rosenbluth technique for determining the ratio of the electric and magnetic form factors of the proton at high $Q^2$, and partly reconciles the apparent discrepancy with the results of the polarization transfer technique.

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P. G. Blunden, W. Melnitchouk, J. A. Tjon. 2003-08-21. Two-photon exchange and elastic electron-proton scattering. https://doi.org/10.1103/physrevlett.91.142304

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