Speaker
Simone Donati
(Uni+INFN Pisa)
Description
The CDF II eXtremely Fast Tracker (XFT) is the trigger processor which
reconstructs charged particle tracks in the transverse plane of the central
tracking chamber. The XFT tracks are also extrapolated to the
electromagnetic calorimeter and muon chambers to generate trigger
electron and muon candidates. The XFT is crucial for the entire CDF II
physics program: it detects high pT leptons from W/Z and heavy flavor
decays and, in conjunction with the Level 2 processors, it identifies
secondary vertices from beauty decays. The XFT has thus been crucial for
the recent measurement of the B 0 s − B 0 s mixing and Σb discovery. The
increase of the Tevatron instantaneous luminosity demanded an upgrade of
the system to cope with the higher occupancy of the chamber. In the
upgraded XFT, three dimensional tracking reduces the level of fake tracks
and measures the longitudinal track parameters, which strongly reinforce
the trigger selections. This allows to mantain the trigger perfectly efficient at
the record luminosities 2 −3 · 10 32 cm−2 s−1 and to mantain intact the
CDF II high luminosity physics program, which includes the Higgs search.
The architecture, the used technology, the performance and the impact of
the upgraded XFT on the entire CDF II trigger strategy are reviewed.
Author
Simone Donati
(Uni+INFN Pisa)
