The D0 Silicon Track Trigger
  The Level-2 Silicon Track Trigger preprocessor (L2 STT) of the D0 detector in Run II is described. It performs a precise reconstruction of charged particle tracks in the Central Fiber Tracker (CFT) and the Silicon Microstrip Tracker (SMT). Events with displaced tracks originating from the decay of long living particles such as B hadrons are triggered on. The presence of b quarks contained in such hadrons is relevant for B physics and crucial as signature of top quark and Higgs boson decays. 
Lars Sonnenschein (for the D0 collaboration)