Inclusive Jet and Dijet Production at the Tevatron

High energy jet distributions measured since 1992 at the Fermilab Tevatron proton--antiproton collider are presented and compared to theoretical predictions. The statistical uncertainties on these measurements are significantly reduced relative to previous results. The systematic uncertainties are comparable in size to the uncertainty in the theoretical predictions. Although some discrepancies between theory and measurements are noted, the inclusive jet and dijet cross sections can be described by quantum chromodynamics. Prospects for reducing the uncertainty in the theoretical predictions by incorporating Tevatron measurements into the proton parton distributions are discussed. Dijet distributions, in excellent agreement with quantum chromodynamics, set a 2.5 TeV limit on the mass of quark constituents.Comment: 49 Pages, 33 Figures, To be published in Annual Review of Nuclear and Particle Science, Vol. 49, (1999

First results from the central tracking trigger of the DO experiment

©2004 IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE.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

The central track trigger of the DO experiment

©2004 IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE.The general purpose DO collider detector, located at Fermi National Accelerator Laboratory, is operated in the high luminosity (L = 2 X 10(32) cm(-2) s(-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

Inclusive jet production at 630 and 1800 GeV

Inclusive jet cross sections measured at the Fermilab Tevatron p{anti p} Collider are presented and compared to theoretical predictions. The cross sections are reported as a function of jet E{sub T} at beam energies of {radical}s = 0.63 TeV and {radical}s = 1.8 TeV. A recent preliminary result at {radical}s = 1.8 TeV by the CDF collaboration confirms an earlier published result which is in good agreement with Quantum Chromodynamics (QCD) below E{sub T} = 250 GeV, but which shows excess jet production above 250 GeV. A final result by the D0 collaboration is in good agreement with QCD at all E{sub T} . An uncertainty analysis, including a final D0 systematic error matrix, indicates the two measurements are consistent. Preliminary {radical}s = 0.63 TeV cross sections from the two experiments are consistent with one another but somewhat lower than QCD predictions. Likewise, preliminary measurements of the ratio of cross sections at {radical}s = 0.63 TeV and {radical}s = 1.8 TeV are experimentally consistent, but approximately 20% below predictions