Bonn 2001 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe
T: Teilchenphysik
T 108: Teilchenidentifikation
T 108.4: Vortrag
Montag, 26. März 2001, 17:00–17:15, HS XIII
Particle Identification with the HERMES RICH detector — •Katarina Negodaeva — DESY-Zeuthen
Hadron separation (kaon, pion and proton) is realized at the HERMES experiment since 1998 via operating a dual-radiator RICH detector. The HERMES RICH is able to identify pions in the momentum range 0.5-16 GeV, kaons between 2 and 16 GeV and protons between 2 and 20 GeV by the combination of likelihoods calculated for each of the radiators, aerogel and C4F10 separately. The probabilities that a hadron type t (K,π,p) is identified as type i (K, π, p, X-not identified) are combined in the probability matrix Pit, where the diagonal elements are the efficiencies and the off-diagonal ones are misidentifications. To extract the efficiency matrix elements particle decays were used as natural clean hadronic samples. The detector operation has a threshold behavior and therefore a momentum dependence. Thus a momentum dependence of the identification efficiencies and contaminations is expected. The dependencies of the Pit matrix elements on the hadron momentum together with possible dependencies of the detector performance on the event topology and position in the detector have been studied. Consistent results on the RICH efficiencies and misidentifications will be presented.