A dilepton spectrometer project for sis

We present an experimental project to study e+e- pairs production in nucleus-nucleus collisions at GSI. Dileptons appear to be a clean probe to investigate in medium properties of nuclear form factors, baryon excitations (DELTA) and mesons (π-dispersion relation; ρ-form factor) at high nuclear matter densities. The design of the detector system will be based on the experience obtained with the DLS-spectrometer at LBL and other dilepton detector systems in operation at high energy facilities. The project includes a fast electron trigger provided by a ring imaging Cherenkov detector with a segmented photomultiplier array. (author)