Search for two photon exchange from $e^{+}+e^{-}\to p+\bar{p}+\gamma$ data

Abstract

We look for asymmetries in the angular distributions of events from recent data on $e^{+}+e^{-}\to p+\bar{p}+\gamma$ from BABAR collaboration. From first principles, as the C-invariance of the electromagnetic interaction and the crossing symmetry, the presence of two-photon exchange would create a forward backward asymmetry in the data. The analysis of the available data shows no asymmetry, within an error of 2%. This result is consistent with a structureless model for the proton, based on a calculation of $e^{+}+e^{-}\to {\mu }^{+}+{\mu }^{-}+\gamma$ with a proper replacement of the muon mass. As no systematic deviations are seen, we can conclude that these data do not give any hint of the presence of the two photon contribution, in all the considered kinematical range.

10 pages 2 figures

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Cited by in corpus (11)

• Review of two-photon exchange in electron scattering
• Study of e+e- --> p anti-p via initial-state radiation at BABAR
• Nucleon Electromagnetic Form Factors in the Timelike Region
• Complete measurement of $\Lambda$ electromagnetic form factors
• Feasibility studies of the time-like proton electromagnetic form factor measurements with PANDA at FAIR
• Two-Photon Exchange Contribution to Proton Form Factors in Time-Like region
• Estiamte of the two-photon exchange effect on deuteron electromagnetic form factors
• General analysis of two--photon exchange in elastic electron--${}^{4}He$ scattering and $e^{+}+e^{-}\to {\pi }^{+}+{\pi }^{-}.$
• Resonances contribution to two-photon exchange effects and possible large forward-backward asymmetry in $e^{+}{e}^{-}\to p\bar{p}$
• $\Delta$ contribution in $e^{+}+e^{-}\to p+\bar{p}$ at small $s$
• Cross section and polarization observables for the reaction $e^{+}+e^{-}\to a_1(1260)+\pi$