Berlin 2005 – wissenschaftliches Programm

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HK: Physik der Hadronen und Kerne

HK 35: Instrumentation und Anwendungen

HK 35.5: Vortrag

Dienstag, 8. März 2005, 18:00–18:15, TU MA144

Electron/Pion Identification with ALICE TRD Prototypes using a Neural Network Algorithm — •Alexander Wilk — Institut für Kernphysik, Wilhelm-Klemm-Straße 9, 48149 Münster

The identification of electrons with a momentum p > 1 GeV/c is one of the most important features of the ALICE Transition Radiation Detector (TRD). We present the e/π identification performance using a neural network algorithm (NN).

The likelihood methods, the usual approach based on the integrated energy deposit, use only part of the information measured with the ALICE TRD. In addition, the amplitude measurement of each time bin can be exploited provided the correlations among the amplitudes of a given event are properly taken into account. The usage of a neural network algorithm is the natural choice for the analysis of such data. We present the latest results for pion rejection using a NN, which increases the pion rejection up to about 500 for a momentum of 2 GeV/c, a significant advantage compared to the standard methods where the pion rejection factor is of the order of 100. We investigate different NN topologies and their effect on the e/π identification. The momentum dependence of the pion rejection is studied in the range 2-6 GeV/c.

This work is supported by BMBF.