2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/201354We summarize our current theoretical understanding of in-medium properties of the electromagnetic current correlator in view of recent dimuon data from the NA60 experiment in In(158 AGeV)-In collisions at the CERN-SPS. We discuss the sensitivity of the results to space-time evolution models for the hot and dense partonic and hadronic medium created in relativistic heavy-ion collisions and the contributions from different sources to the dilepton-excess spectra.To appear in the proceedings of the 19th International Conference on Ultra-Relativistic Nucleus-Nucleus Collisions (Quark Matter 2006) v2: references added, minor typos correctedHigh Energy Physics - PhenomenologyNuclear ExperimentNuclear Theorytext