Triggering on B-Jets at CDF II

In this paper we present a trigger able to online select b-jets enriched samples. This feature is of central interest in order to extend the physics reach for Standard Model or Minimal Super Symmetric Model Higgs decaying into a pair of b-quarks. The algorithm fully exploits the recently upgraded CDFII tracking system (XFT - eXtremely Fast Tracker) and Level 2 CALorimeter (L2CAL) cluster finder. These upgrades, necessary to cope with Tevatron increasing luminosity, have provided new and refined trigger primitives which, in conjunction with the already existing Silicon Vertex Trigger (SVT), are at the basis of our algorithm. As a b-quark can travel some millimeters before hadronizing, the trigger architecture is based on the search of tracks displaced with respect to the primary vertex and matching energetic jets of particles. We discuss the development of the trigger, its technical implementation as well as its performances: the algorithm can provide high efficiency on H → bb̄ events and run up to the highest luminosity reached by Tevatron so far with an acceptable occupancy of the available bandwidth.