2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/47104I discuss the impact of color-octet contributions to inclusive $J/ψ$ photoproduction at HERA. Emphasis is put on resolved photon processes and on $J/ψ$ polarization, which will be experimentally accessible at HERA in the near future. Both analyses provide a powerful test of the NRQCD factorization approach to charmonium production.LaTeX, 10 pages, 3 figures; uses epsf style. Talk presented at the Ringberg Workshop ``New Trends in HERA Physics'', Castle Ringberg, Tegernsee, Germany, 25-30 May 1997, to appear in the proceedingsHigh Energy Physics - Phenomenologytext