The DO central track trigger Olsen, J.; Anderson, J.; Angstadt, R. ...
IEEE transactions on nuclear science,
2004-June, 2004-06-00, 20040601, Letnik:
51, Številka:
3
Journal Article
Recenzirano
Odprti dostop
An overview of the system architecture and algorithms used for the DO Central Track Trigger (CTT) in the Run 2 of the Fermilab Tevatron Proton-Antiproton Collider is presented. This system uses ...information from the newly commissioned Central Fiber Tracker and Preshower Detectors to generate Level 1 trigger decisions. It also generates lists of seed tracks and preshower clusters that are sent to the Level 1 Muon Trigger, L2 Silicon Track Trigger, and Central and Forward Preshower Level 2 preprocessors. The system consists of modular boards which utilize field-programmable gate arrays (FPGAs) to implement trigger algorithms. The system delivers trigger decisions every 132 ns, based on input data flowing at a maximum sustained rate of 475 gigabits per second. The first results of trigger efficiency studies are presented.
Nontriviality of the linear sigma model Babukhadia, L.R.; Scadron, M.D.
The European physical journal. C, Particles and fields,
05/1999, Letnik:
8, Številka:
3
Journal Article
Recenzirano
Odprti dostop
We consider techniques (based on an ultraviolet cutoff) used to prove that the pure boson (\(\phi^4)_4\) field theory is trivial and apply them instead to the dynamically generated quark-level linear ...sigma model. This cutoff approach leads to the conclusion that the latter field theory is in fact nontrivial.
The central track trigger of the DO experiment Yuan Hu; Anderson, J.; Angstadt, R. ...
IEEE transactions on nuclear science,
2004-Oct., 2004-10-00, 20041001, Letnik:
51, Številka:
5
Journal Article
Recenzirano
Odprti dostop
The general purpose DO collider detector, located at Fermi National Accelerator Laboratory, is operated in the high luminosity (L=2/spl times/10/sup 32/ cm/sup -2//spl middot/s/sup -1/) and ...high-collision-rate environment (396 ns between beam crossings) of the upgraded Tevatron proton anti-proton accelerator. DO uses a three-tiered trigger system to select events for offline storage and analysis. This paper describes the architecture and performance of the DO central track trigger (CTT) system based on the new central fiber tracker, central preshower and forward preshower detectors, with emphasis on the interface to and integration with the second tier L2 Trigger system.
An overview of the DO Central Track Trigger (CTT) for the Tevatron Run 2 program is presented. This newly commissioned system uses information from the DO Central Fiber Tracker and Preshower ...Detectors to generate trigger information for the first level of the three-tiered DO Trigger. The system delivers tracking detector trigger decisions every 132 ns, based on input data flowing at a rate of 475 Gbit per second. Initial results indicate excellent performance of the CTT. First studies of efficiency and trigger performance of the CTT are presented.
We report a search for effects of large extra spatial dimensions in pp collisions at a center-of-mass energy of 1.8 TeV with the D0 detector, using events containing a pair of electrons or photons. ...The data are in good agreement with the expected background and do not exhibit evidence for large extra dimensions. We set the most restrictive lower limits to date, at the 95% C.L. on the effective Planck scale between 1.0 and 1.4 TeV for several formalisms and numbers of extra dimensions.
The upgraded D0 detector Abazov, V.M.; Abbott, B.; Abolins, M. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
2006, Letnik:
565
Journal Article
Recenzirano
The D0 experiment enjoyed a very successful data-collection run at the Fermilab Tevatron collider between 1992 and 1996. Since then, the detector has been upgraded to take advantage of improvements ...to the Tevatron and to enhance its physics capabilities. We describe the new elements of the detector, including the silicon microstrip tracker, central fiber tracker, solenoidal magnet, preshower detectors, forward muon detector, and forward proton detector. The uranium/liquid-argon calorimeters and central muon detector, remaining from Run I, are discussed briefly. We also present the associated electronics, triggering, and data acquisition systems, along with the design and implementation of software specific to D0.
We examine properties of $t\overline{t}$ candidate events in lepton + jets final states to establish the helicities of W bosons in $t\rightarrow$W+b$ decays. Our analysis is based on a direct ...calculation of a probability density for each event to correspond to a $t\overline{t}$ final state, as a function of the helicity of the $W$ boson. Using the 125 events/pb of data collected by the D0 experiment at the Fermilab Tevatron $p\overline{p}$ Collider at $\sqrt{s}$=1.8 TeV, we obtain a longitudinal helicity fraction $F_0$=0.56$\pm$0.31, consistent with the prediction of $F_0$=0.70 from the standard model.
Using the exclusive decay B^0_s -> J/psi (mu+mu-) phi(K+K-), we report the most precise single measurement of the B^0_s lifetime. The data sample corresponds to an integrated luminosity of ...approximately 220 pb-1 collected with the DO detector at the Fermilab Tevatron Collider in 2002-2004. We reconstruct 337 signal candidates, from which we extract the B^0_s lifetime, \tau(B^0_s) = 1.444 +0.098/-0.090 stat +/- 0.020 sys ps. We also report a measurement for the lifetime of the B^0 meson using the exclusive decay B^0 -> J/psi (mu+mu-)K*0(892)(K+pi-). We reconstruct 1370 signal candidates, obtaining \tau(B^0) = 1.473 +0.052/-0.050 stat +/- 0.023 sys ps, and the ratio of lifetimes, \tau(B^0_s)/\tau(B^0) = 0.980 +0.075/-0.070 stat +/- 0.003 sys.
PDF
