2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/166619The amplitude for photoproduction gamma p -> Υp is calculated in a pQCD k_\perp-factorization approach. The total cross section for diffractive Υ's is compared to recent HERA data. The amplitude is used to predict the cross section for exclusive ppbar \to ppbar Υ(1S,2S) process in hadronic reactions at Tevatron energies. We also included absorption effects.4 pages, 3 figures, a talk given by A.R. at MESON2008, 6 - 10 June 2008, Kraków, PolandHigh Energy Physics - Phenomenologytext