  HADES is the only operating dielectron spectrometer in the energy regime 1-2
AGeV. The physics program aims at a systematic investigation of dielectron
production in heavy ion as well as elementary and pion-induced reactions.
  This contribution highlights recent results on electron pair production in
C12+C12 collisions at an incident energy of 2 AGeV with HADES. The measured
pair production probabilities span over five orders of magnitude. Dalitz decays
of pi0 and eta account for all the yield up to 0.15 GeV/c2, but for only about
50% above this invariant mass. The excess yield compared to the hadronic
cocktail between the pi0-Dalitz and the rho/omega invariant-mass region is in
agreement with the former DLS result if one assumes that it scales with beam
energy like pion production. Preliminary results from C12+C12 collisions at an
incident energy of 1 AGeV support this scenario.
