Design and performance of the level 1 calorimeter trigger for the BABAR detector
IEEE T NUCL SCI 48:3 (2001) 541-546
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, CA. This experiment requires a very large data sample and the PEP-Il 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 analyzed 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, implementation, construction and performance of the Level 1 Calorimeter Trigger during the first year of BABAR operation are presented.Search for Narrow Diphoton Resonances and for gamma-gamma+W/Z Signatures in p\bar p Collisions at sqrt(s)=1.8 TeV
ArXiv hep-ex/0105066 (2001)
Measurement of the two-jet differential cross section inp p ¯ collisions ats = 1800 GeV
Physical Review D American Physical Society (APS) 64:1 (2001) 012001
Measurement of dijet production in neutral current deep inelastic scattering at high Q2 and determination of αs
Physics Letters Section B Nuclear Elementary Particle and High Energy Physics 507:1-4 (2001) 70-88
Abstract:
Dijet production has been studied in neutral current deep inelastic e+p scattering for 470 < Q2 < 20000 GeV2 with the ZEUS detector at HERA using an integrated luminosity of 38.4 pb-1. Dijet differential cross sections are presented in a kinematic region where both theoretical and experimental uncertainties are small. Next-to-leading-order (NLO) QCD calculations describe the measured differential cross sections well. A QCD analysis of the measured dijet fraction as a function of Q2 allows both a precise determination of αSearch for neutral supersymmetric Higgs bosons in pp collisions at sqrt[s] = 1.8TeV.
Phys Rev Lett 86:20 (2001) 4472-4478