Real-time b jet identification in ATLAS

There are interesting physics processes studied at the ATLAS detector at the LHC, whose signatures contain jets originating from quarks (at least one of which originates from a bottom quark), but no charged lepton: top quark pair production where both quarks decay hadronically, Higgs boson produced in vector boson fusion and decaying to a bottom quark pair, or supersymmetric signatures with no charged lepton. Data for these processes can only be collected using jet-based triggers. As LHC instantaneous luminosity increases and ATLAS trigger bandwidths are constant, jet energy thresholds need to be raised, which decreases offline analysis sensitivity due to a lower signal acceptance. However, the need to raise jet thresholds can be made less pressing if jets originating from bottom quarks are identified as such (b tagging) already at the trigger stage.