2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/36907The H1 and ZEUS collaborations at HERA report new data on the diffractive production of vector mesons with a many-fold increase of luminosity compared to previous measurements. The new data include photoproduction and electroproduction of $ρ^0,ϕ,J/ψ$. The available data on elastic VM production indicate that the interaction scales as $Q^2+M_{V}^2$.4 pages, 3 Figures, LatexHigh Energy Physics - Experimenttext