The HADES (High Acceptance Di-Electron Spectrometer) is a tool designed for lepton pair (e⁺e^-) spectroscopy in pion, proton and heavy ion induced reactions in the 1–2AGeV energy range. One of the goals of the HADES experiment is to study in-medium modifications of hadron properties like effective masses, decay widths, electromagnetic form factors etc. Such effects can be probed with vector mesons (ρ, ω, φ) decaying into e⁺e^- channel. The identification of vector mesons by means of a HADES spectrometer is based on invariant mass reconstruction of e⁺e^- pairs. The combined information from all spectrometer sub-detectors is used to reconstruct the di-lepton signal.

Configuration of the HADES experiment