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HK: Fachverband Physik der Hadronen und Kerne
HK 11: Instrumentation
HK 11.7: Talk
Monday, March 19, 2012, 18:15–18:30, P 2
Online Electron Identification for Triggering with the ALICE Transition Radiation Detector — •Benjamin Heß — Physikalisches Institut, Universität Heidelberg
The ALICE Transition Radiation Detector (TRD) is a fast tracker with good e/π-separation for high momenta already at the trigger level. It can be used to enhance rare probes such as high-pt jets and electrons. For the latter, a strategy for Particle Identification (PID) based on look-up tables containing the electron likelihoods for different deposited charges has been studied. The deposited charge of electrons is higher than that of pions due to a higher specific energy loss and a much more probable emission of transition radiation.
Monte Carlo simulations have been used to systematically investigate the PID performance. The best achievable pion suppression was found to be around 40 for an electron efficiency of 90%.
The PID performance depends on several parameters, like gas gain and drift velocity. The simulations showed that the gas gain changes critically limit the stability of the PID performance and that a stable drift velocity is also important.
The results of these studies allow to assess the tolerances of gas gain and drift velocity that are required for a reliable PID performance.