2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/98528We present prospects and requirements for the study at HERA of hard photon processes which generate high $p_T$ photons in the final state, and processes which generate Drell-Yan lepton pairs.6 pages, 3 embedded figures. To appear in the proceedings of the workshop "Future physics at HERA"High Energy Physics - Phenomenologytext