CAN EXTENDED DUALITY UNIQUELY EXPLAIN THE DILEPTON DATA IN HIC'S AT SPS?

Extended duality (i.e. the replacement of the thermal dilepton emissivity of hadron matter by that of q bar q annihilation)
is used to explain the dilepton data of heavy-ion experiments at CERN-SPS. Taking into account the background contributions (hadronic cocktail, Drell-Yan, semileptonic open charm decays) the spectral shapes of the CERES, NA38/50 and HELIOS-3 data in experiments with lead and sulfur beams can be well described while the normalizations of the sulfur beam data is problematic.