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arXiv · hep-ex/0003020

Elastic Photoproduction of J/psi and Upsilon Mesons at HERA

H1 Collaboration·C. Adloff
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Abstract

Cross sections for elastic photoproduction of J/Psi and Upsilon mesons are presented. For J/Psi mesons the dependence on the photon-proton centre-of-mass energy W_gammap is analysed in an extended range with respect to previous measurements of 26<=W_gammap<= 285 GeV. The measured energy dependence is parameterized as sigma_gammap proportional W_gammap^delta with delta=0.83+-0.07. The differential cross section dsigma/dt for J/Psi mesons is derived, its dependence on W_gammap and on t is analysed and the effective trajectory (in terms of Regge theory) is determined to be alpha(t)=(1.27+-0.05)+(0.08+-0.17)*t/GeV^2. Models based on perturbative QCD and on pomeron exchange are compared to the data.

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H1 Collaboration, C. Adloff. 2000-03-16. Elastic Photoproduction of J/psi and Upsilon Mesons at HERA. https://doi.org/10.1016/s0370-2693(00)00530-x

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