Baryonic contributions to the dilepton spectrum of nucleon-nucleon collisions

Abstract

We study the production of dileptons in relativistic nucleon-nucleon collisions. Additionally to the traditional dilepton production channels (vector meson decays, meson and Delta(1232) Dalitz decays) we included in our model as new dilepton sources the Dalitz decay of higher unflavored baryon resonances with spin<=5/2 and mass<=2.25 GeV/c^2. The contributions of these new channels are estimated using experimental information about the Ngamma decays of the resonances and have large uncertainties. The obtained dilepton spectra are compared to the experimental data by the DLS collaboration. Predictions for the HADES detector (SIS, GSI) are also discussed. In spite of the large uncertainties of the higher resonance Dalitz decay contributions we are able to draw the conclusion that these contributions are negligible compared to the other dilepton sources and do not influence the detectability of the phi and omega vector meson peaks.