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arXiv · 1804.06665

Two-Photon Exchange: Future experimental prospects

Jan C. Bernauer
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Abstract

The proton elastic form factor ratio is accessible in unpolarized Rosenbluth-type experiments as well as experiments which make use of polarization degrees of freedom. The extracted values show a distinct discrepancy, growing with $Q^2$. Three recent experiments tested the proposed explanation, two-photon exchange, by measuring the positron-proton to electron-proton cross section ratio. In the results, a small two-photon exchange effect is visible, significantly different from theoretical calculation. Theory at larger momentum transfer remains untested. This paper discusses the possibilities for future measurements at larger momentum transfer.

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Jan C. Bernauer. 2018-04-18. Two-Photon Exchange: Future experimental prospects. https://doi.org/10.1007/s00601-018-1439-y

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