ATLAS Experiment © 2014 CERN


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About FTK

The Fast TracKer (FTK) is a hardware track finder for the ATLAS trigger system which is planned to operate in 2015. FTK can identify important physics processes through their track-based signatures. Many new physics extensions to the standard model (SM) yield enhanced production of b quarks and tau leptons as a result of non-SM interactions. Since b quarks have a long lifetime and large mass as compared to most quarks, they tend to leave a track-based signature of a displaced vertex several millimiters from the primary interaction. Tau lepton can be identified through their hadronic decays to multiple pions which produce narrow jet cones containing 1 or 3 tracks. The FTK allows the possibility of rapid b-quark and tau lepton identification within the online trigger system by providing a list of tracks with excellent resolution at the start of Level 2 processing. This will provide the experiment with much flexibility for identifying new physics signatures with higher efficiency while reducing trigger rates.

At the same time, as instantaneous luminosities increase the number of additional interactions in each bunch crossing rises. The FTK will allow us to maintain low trigger rates and high efficiency for electrons and muons by asking for lepton isolation only using tracks that point to the interaction vertex that produced the lepton. The FTK will also be able to provide a complete list of near-offline quality tracks by the time Level-2 processing begins, which can be used in conjunction with calorimeter and muon information to further constrain the event characteristics of interesting physics processes.