2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/48744We study the prospects to get information about the early and hot stages of deconfined matter produced in relativistic heavy-ion collisions by analyzing dilepton and single-lepton spectra. Energy losses of heavy quarks in deconfined matter and thermalization effects in hadron matter and their influence on lepton spectra are considered.8 LaTeX pages including eps figures, contribution to the 37th International Winter Meeting on Nuclear Physics, Bormio, Jan 25-29, 1999High Energy Physics - Phenomenologytext