Simulation studies of electron identification with the RICH detector for CBM

The measurement of dielectron pairs in heavy-ion collisions at FAIR energies requires detectors which identify electrons with high efficiency and reject pions by a factor of 10 at least. Electron identification in CBM will be performed by a Ring Imaging Cherenkov (RICH) detector (for momenta up to about 10 GeV/c) and a Transition Radiation Detector (TRD) [1, 2]. Main sources of a misidentification of pions as electrons in the RICH are mismatches of electron rings with pion tracks, e.g. from secondary electrons without a reconstructable track in the STS and primary vertex pions. Moreover, misidentification of pions at higher momenta due to the finite resolution of the ring radius measurement will occur. In order to study the proposed RICH detector layout with respect to the π rejection requirements simulations have been started and first results are presented in this report for both of these sources.