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Heavy Quarkonium Photoproduction at HERA and Charm Content of the Photon

Saleev V. A
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Abstract

A study of the $\J$-meson photoproduction at large transverse momentum at HERA energies via the charm quark excitation in the photon is presented. Based on perturbative QCD, nonrelativistic quark model and photon structure function formalism, our calculation demonstrates that the charm content of the photon may be very important for the $\J$ photoproduction at the large transverse momentum. It is shown that at HERA energies $\J$ production via the subprocess $\cg$ dominates over the resolved photon contribution via the gluon-gluon fusion at $\pt\ge 2$ GeV/c and over the leading order direct photon-gluon fusion contribution at $\pt\geq 15$ GeV/c.

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Saleev V. A. 1995-11-22. Heavy Quarkonium Photoproduction at HERA and Charm Content of the Photon. https://arxiv.org/abs/hep-ph/9511390

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