The level 1 central and forward tracking trigger for the DØ upgrade

The upgraded DØ detector will allow for a wide variety of physics studies that fully exploit the peak instantaneous luminosity of 2×10³² cm^-2 s^-1 at Run II of the Tevatron. Many of these topics rely heavily on the ability to trigger on electrons, photons, and muons over a large region of phase space. The level 1 trigger at DØ is designed to handle an input data rate of 7.6 MHz and deliver and output data rate of 7 KHz. The tracking trigger, which forms a significant part of the DØ level 1 trigger, uses data from a scintillating fiber tracker, central and forward preshower detectors, calorimeters, and muon detectors. Tracks with transverse momentum greater that 1.5 GeV are found using the scintillating fiber tracker. The preshower detectors detect energy clusters above preprogrammed thresholds left by electromagnetic particles. The information is sent to a level 1 trigger framework to be matched with information from the calorimeters to form a level 1 trigger. Large Field Programmable Gate Arrays (FPGA´s) are used to code the complex trigger logic, which also allows for extension and flexibility in trigger programming