Coulomb distortion and experimental mass resolution in dielectron spectroscopy at relativistic energy

We present a classical estimate of the Coulomb effect on dielectron invariant mass measurements at intermediate energy (about 1 GeV). Simplified simulations of the reactions π−(1.3 GeV/c)+Au→ω+X and Au(1−1.6 GeV/A)+Au→ω+X are used for both the Coulomb distortion estimate and the investigation of the capability for ω in-medium mass shift observation. The Coulomb distortion is found at the 1% level, similar to typical experimental resolutions. Direct mass shift observation is significantly obscured, and the hadronic medium effect mostly translates into a weakening of the ω outside decay peak.