The pattern recognition method for the CsI-RICH detector in ALICE

The High Momentum Particle Identification Detector in the ALICE experiment is based on a Ring Imaging Cherenkov (RICH) detector with a CsI photocathode. The identification of Cherenkov photons, especially in conditions of high occupancy as will be the case in Pb–Pb collisions at the Large Hadron Collider, requires efficient pattern recognition algorithms. The results of an algorithm based on the Hough transform, that maps the pad coordinate space directly to the Cherenkov angle parameter space, will be shown. The performance of the method on real events collected in the STAR experiment at the Relativistic Heavy Ion Collider (RHIC) at Brookhaven (USA), where a prototype of the RICH detector developed in the ALICE framework has been successfully operated, will also be described.