[en] Experimental results on the photoproduction of cumulative protons on 12C are presented versus the light scaling variable α and Psub(perpendicular). The structure function f(α, Psub(perpendicular)sup(2)) is shown to be factorized for α > 1 and Psub(perpendicular) >= 0.5 GeV/c; f(α, Psub(perpendicular)sup(2))=fsub(1)(α)xfsub(2)(Psub(perpendicular)sup(2)). The functions f1(α) and fsub(2)(Psub(perpendicular)sup(2)) here have an exponential form