The performance of the BaBar DIRC

 Jochen Schwiening

The BaBar DIRC, a novel type of Cerenkov ring imaging device, is the primary hadronic particle identification system for the BaBar detector at the PEP-II asymmetric B-Factory at SLAC. The DIRC images the light trapped by internal reflection in long fused slica bars that serve simultaneously as the Cerenkov radiator and as light guides.

The light is transported down the bars to an imaging region located outside the detection region, where the images are formed and observed in a array of photomultiplier tubes. BaBar begin taking date with colliding beams in late spring of 1999. This talk will describe the PID performance attained by the DIRC, and will highlight some representative physics channels that use DIRC particle ID.