Resonance production and decay in pion induced collisions with HADES

Federico Scozzi, Y. Foka, N. Brambilla, V. Kovalenko
2017 EPJ Web of Conferences  
The main goal of the High Acceptance Di-Electron experiment (HADES) at GSI is the study of hadronic matter in the 1-3.5 GeV/nucleon incident energy range. HADES results on e + e − production in proton-nucleus reactions and in nucleus-nucleus collisions demonstrate a strong enhancement of the dilepton yield relative to a reference spectrum obtained from elementary nucleon-nucleon reactions. These observations point to a strong modification of the in-medium ρ spectral function driven by the
more » ... driven by the coupling of the ρ to baryon-resonance hole states. However, to scrutinize this conjecture, a precise study of the role of the ρ meson in electromagnetic baryon-resonance transitions in the time-like region is mandatory. In order to perform this study, HADES has started a dedicated pion-nucleon programme. For the first time a combined measurement of hadronic and dielectron final states have been performed in π − -N reactions at four different pion beam momenta (0.656, 0.69, 0.748 and 0.8 GeV/c). First results on exclusive channels with one pion π − -p and two pions (nπ + π − , pπ − π 0 ) in the final state, which are currently analysed within the partial wave analysis (PWA) framework of the Bonn-Gatchina group, are discussed. Finally first results for the dielectron analysis will be shown. a
doi:10.1051/epjconf/201713705023 fatcat:thzoq42xn5ecbo2qkthbj24u44