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arXiv · 1112.4615

Resonances contribution to two-photon exchange effects and possible large forward-backward asymmetry in $e^+ e^- \rightarrow p \bar{p}$

Hai-Qing Zhou·Bing-Song Zou
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Abstract

The resonances ($η_c,χ_{c0,c2}$) contribution to two-photon exchange (TPE) effects in $e^+ e^- \leftrightarrow p \bar{p}$ is calculated in a simple hadronic model. The calculation shows the TPE contributions by resonance $χ_{c2}$, which are dependent on the unknown phases $ϕ_{E,M}$ of proton's time-like form factors $G_{E,M}$, are much larger than the TPE contributions by non-resonance and are comparable with measurement precision of coming PANDA detector at $\sqrt{s} \sim M_{χ_{c2}}$ for most $ϕ_{E,M}$.

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Hai-Qing Zhou, Bing-Song Zou. 2012-04-26. Resonances contribution to two-photon exchange effects and possible large forward-backward asymmetry in $e^+ e^- \rightarrow p \bar{p}$. https://doi.org/10.1016/j.nuclphysa.2012.04.004

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