Dilepton Production at SPS-energy Heavy Ion Collisions
  The production of dileptons is studied within a hadronic transport model. We investigate the sensitivity of the dilepton spectra to the initial configuration of the hadronic phase in a ultrarelativistic heavy ion collision. Possible in medium correction due to the modifications of pions and the pion form factor in a hadronic gas are discussed. 
V. Koch, C. Song (Lawrence Berkeley National Laboratory)