The CLEO-III trigger: Calorimetry and tracking

The CLEO-III Trigger provides a trigger decision every 42 ns, with a latency of approximately 2.5 /spl mu/s. This paper describes the pipelined signal processing and pattern recognition schemes used by the calorimeter, and the axial and stereo portions of the drift chamber, to provide the information necessary to make these decisions. Field programmable gate arrays are used extensively to provide cluster filtering and location sorting for calorimetry, and path finding for tracking. Analog processing is also employed in the calorimetry to provide additional leverage on the problem. Timing information is extracted from both calorimetry and tracking.