The identification of rare charged kaons in heavy-ion collisions at relativistic energies by time-of-flight with the HADES spectrometer

Detailed performance simulations of the HADES RPC time-of-flight wall have been undertaken. The most delicate situation is the identification of K − mesons close to the mid-rapidity region. While momentum resolution does not appear to be an issue, the small non-Gaussian tails in the time response are a clear problem. It will be argued that the use of redundant information supplied by time coincidence between the two layers (possible in the HADES design) can drastically improve the situation. The uniformity of acceptance for the two layer coincidence will be discussed. A possible distortion to the reconstructed kaon flow due to the wall occupancy, which is not isotropic with respect to the reaction plane because of the flow pattern of the much more abundant protons, pions and deuterons, has also been studied.