Recognition of Cherenkov Ring Patterns with the HMPID-RICH Detector in ALICE at LHC

A high momentum particle identification detector (HMPID) covering about 50f the ALICE central barrel region has been designed and prototyped.<P>The detector consists of seven RICH modules with a proximity focusing geometry, covering 12m<SUP>2</SUP>. The very large density of hits on the detector (80&divide;90 part/m<SUP>2</SUP> in the extreme cases) makes the recognition of the Cherenkov photon patterns a complex and crucial task. A study of the pattern recognition based on the Hough transformation in terms of particle identification efficiency and particle contamination will be presented.