2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/46524Nuclear shadowing arises from multiple scattering of the hadronic fluctuations of the virtual photon in a nucleus. We predict different longitudinal and transverse shadowing and an A-dependence of R which can be up to a 50% effect. The possibility of detecting nuclear effects on R at HERA is discussed.latex, 6 pagesHigh Energy Physics - Phenomenologytext