2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/45493In many ways the pomeron is like the photon, but there are important differences. Factorisation allows us to define a pomeron structure function, even though the pomeron is not a particle. Although we have a model for the light-quark content of the pomeron, which led to the prediction that a surprisingly large fraction of events at HERA would have an extremely-fast final-state proton, its charm and gluon content will have to be got from experiment. Because the pomeron is not a particle, we cannot derive a momentum sum rule.4 pages including 3 figures, uuencoded ps file Based on talks given in April 1995 at Photon '95 (Sheffield) and DIS '95 (Paris)High Energy Physics - Phenomenologytext