First particle identification with a Disc-DIRC detector

The PANDA experiment at the future FAIR laboratory at GSI in Darmstadt, Germany, will require excellent particle identification for its study of proton-antiproton reactions in the few GeV energy range. In the confined space of the PANDA Target Spectrometer, two RICH-type Cherenkov detectors mainly aim at pion-kaon separation: a Barrel-DIRC detector patterned after the BaBar-DIRC covering the central angles and a Disc-DIRC detector for the forward theta angle range from 5° to 22°. Such a Disc-DIRC design has not yet been used in particle physics experiments. A demonstrator prototype, one quarter segment scaled to 80% of the PANDA geometry, constructed at Giessen university and equipped with 480 sensor pixels, has measured particles of several GeV/c in a secondary mixed beam delivered by the PS T9 test beamline at CERN in October 2012. A first analysis of the recorded hit patterns is presented.