EPJ

2023 Impact factor 4.2
EPJ C - Particles and Fields
Particles and Fields
Eur. Phys. J. C 29, 45-58 (2003)
DOI: 10.1140/epjc/s2003-01215

Nonperturbative QCD treatment of $J/\Psi$ photoproduction

H.G. Dosch1 and E. Ferreira2

1  Institut für Theoretische Physik, Universität Heidelberg, Philosophenweg 16, 69120 Heidelberg, Germany
2  Instituto de Física, Universidade Federal do Rio de Janeiro, C.P. 68528, Rio de Janeiro 21945-970, RJ, Brazil


(Received: 20 December 2002 / Revised version: 12 March 2003 / Published online: 13 May 2003)

Abstract
We present a nonperturbative QCD calculation of elastic $J/\psi$ meson production in photon-proton scattering at high energies. Using light cone wave functions of the photon and vector mesons, and the framework of the model of the stochastic QCD vacuum, we calculate the differential and integrated elastic cross sections for $\gamma~p \rightarrow J/\psi~p $. With an energy dependence following the two-pomeron model we are able to give a consistent description of the integrated cross sections and the differential cross sections at low |t| in the range from 20 GeV up to the highest HERA energies. We discuss different approaches to introduce rescattering corrections and find no specific effects up to energies presently available. We also calculate and compare to experiments the cross section for $\Upsilon$ photoproduction.



© Società Italiana di Fisica, Springer-Verlag 2003

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