2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/81810QCD sum rules are evaluated at finite nucleon densities and temperatures to determine the change of pole mass parameters for the lightest vector mesons $ρ$, $ω$ and $ϕ$ in a strongly interacting medium at conditions relevant for the starting experiments at HADES. The role of the four-quark condensate is highlighted. A few estimates (within a fire ball model and BUU calculations) of dilepton spectra in heavy-ion collisions at 1 AGeV are presented.contribution to the XL International Winter Meeting on Nuclear Physics, Bormio (Italy), January 20 - 26, 2002Nuclear Theorytext