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Indication of anomalous exchange in exclusive charmonium photoproduction

A. Sibirtsev·S. Krewald·A. W. Thomas
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Abstract

We find that available data on $J/Ψ$ photoproduction at $|t|{\ge}$1 GeV are energy independent over the range $22{\le}\sqrt{s}{\le}170$ GeV and show a very soft $t$ dependence. Through a systematic analysis of the data we detect a new trajectory, which manifests itself at threshold and is energy independent. The trajectory couples to the axial form factor of the nucleon and can reproduce the $J/Ψ$ exclusive photoproduction data at large -$t$.

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A. Sibirtsev, S. Krewald, A. W. Thomas. 2003-10-06. Indication of anomalous exchange in exclusive charmonium photoproduction. https://arxiv.org/abs/nucl-th/0310021

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