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arXiv · 2008.13439

Near-threshold photoproduction of $J/\psi$ in two-gluon exchange model

Fancong Zeng·Xiao-Yun Wang·Li Zhang·Ya-Ping Xie·Rong Wang·Xurong Chen
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Abstract

The near-threshold photoproduction of $J/\psi$ is regarded as one golden process to unveil the nucleon mass structure, pentaquark state involving the charm quarks, and the poorly constrained gluon distribution of the nucleon at large $x$ ($>0.1$). In this paper, we present an analysis of the current experimental data under a two-gluon exchange model, which shows a good consistency. Using a parameterized function form with three free parameters, we have determined the nucleonic gluon distribution at the $J/\psi$ mass scale. Moreover, we predict the differential cross section of the electroproduction of $J/\psi$ as a function of the invariant mass of the final hadrons $W$, at EicC, as a practical application of the model and the obtained gluon distribution. According to our estimation, thousands of $J/\psi$ events can be detected per year on EicC near the threshold. Therefore, the relevant experimental measurements are suggested to be carried out on EicC.

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Fancong Zeng, Xiao-Yun Wang, Li Zhang, Ya-Ping Xie, Rong Wang, Xurong Chen. 2020-08-31. Near-threshold photoproduction of $J/\psi$ in two-gluon exchange model. https://doi.org/10.1140/epjc%2Fs10052-020-08584-6

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