Rapid 3D track reconstruction with the BABAR trigger upgrade

A new hardware trigger system based on tracks detected by a stereo drift chamber has been developed for the BABAR experiment at Stanford Linear Accelerator Center. The z0 pT Discriminator (ZPD) is capable of fast, 3-dimensional reconstruction of charged particle tracks, and provides rejection of background events due to beam particles interacting with the beam pipe at the first-level trigger. Over 1 gigabyte of data is processed per second by each ZPD module. Rapid track reconstruction has been realized by the use of the latest-generation FPGAs.