Dilepton Analysis in the HADES Spectrometer for C+C at 2AGeV  

The high-acceptance dielectron spectrometer HADES has become operational at
GSI Darmstadt.  The primary physics program is to study in medium changes of
light vector mesons via their e+e- decays. The methods of dilepton signal
reconstruction in the HADES spectrometer and preliminary dilepton spectra
for C+C reactions at 2AGeV are presented. In the signal reconstruction
particularly important is the reduction of the huge combinatorial background
arising from e+e- combinations of the leptons from gama conversion in
materials with other leptons in the collision. A purity of the dilepton
signal is determined by using GEANT simulation with the full HADES geometry
and a realistic detector response.