The performance of the HERA-B RICH

Abstract A new approach to study the performance characteristics of the HERA-B RICH using momenta reconstructed with RICH track direction measurements is presented. The particle identification performance is found to meet design specifications: electron–pion separation for momenta up to 15 GeV/ c , pion–kaon separation to 54 GeV/ c . The normalized photo-electron yield is found to be 42±5 cm −1 rad −2 and the single-photon angular resolution is better than 0.7 mrad.