Design and performance of the level 1 calorimeter trigger for the BaBar detector
IEEE Nuclear Science Symposium and Medical Imaging Conference 2 (2000)
Abstract:
Since May 1999 the BaBar detector has been taking data at the PEP-II asymmetric electron-positron collider at the Stanford Linear Accelerator Center. California. This experiment requires a very large data sample and the PEP-II accelerator uses intense beams to deliver the high collision rates needed. This poses a severe challenge to the BaBar trigger system, which must reject the large rate of background signals resulting from the high beam currents whilst accepting the collisions of interest with very high efficiency. One of the systems that performs this task is the Level 1 Calorimeter Trigger, which identifies energy deposits left by particles in the BaBar calorimeter. It is a digital, custom, fixed latency system which makes heavy use of high-speed FPGA devices to allow flexibility in the choice of data filtering algorithms. Results from several intermediate processing stages are read out, allowing the selection algorithm to be fully analysed and optimized offline. In addition, the trigger is monitored in real time by sampling these data and cross-checking each stage of the trigger calculation against a software model. The design, implmentation, construction and performance of the Level 1 Calorimeter Trigger during the first year of BaBar operation are presented.Measurement of sin 2β from B→J/φK s 0 with the CDF detector
Physical Review D 61:7 (2000)
Abstract:
This paper reports an updated measurement of the standard model CP violation parameter sin 2β using the CDF Detector at Fermilab. The entire run I data sample of 110 pb -1 of proton-antiproton collisions at √s = 1.8 TeV is used to identify a signal sample of ∼400 B→J/φK s0 events, where J/φ→μ + μ - →μ + μ - . The flavor of the neutral B meson is identified at the time of production by combining information from three tagging algorithms: a same-side tag, a jet-charge tag, and a soft-lepton tag. A maximum likelihood fitting method is used to determine sin 2β=0.79 -0.44+0.41 (stat+syst). This value of sin 2β is consistent with the standard model prediction, based upon existing measurements, of a large positive CP-violating asymmetry in this decay mode. ©2000 The American Physical Society.Measurement of the Decay Amplitudes ofB 0 → J / ψ K * 0 andB s 0 → J / ψ φ Decays
Physical Review Letters American Physical Society (APS) 85:22 (2000) 4668-4673
Search for the Supersymmetric Partner of the Top-Quark in $p \bar{p}$ Collisions at $\sqrt{s} = 1.8 {\rm TeV}$
ArXiv hep-ex/0011004 (2000)
Dijet production by double pomeron exchange at the fermilab tevatron
Physical review letters 85:20 (2000) 4215-4220