173983707
Detecting High Mass H 0 A 0 Pairs at a 1 TeV Linear Collider
This note describes results from a study ofH0A0 associated production at a linear e+e− collider with √ s = 1.0 TeV. For the values of tanβ as well as the H0 and A0 masses considered here, the dominant decay mode is bb pairs. This fully hadronic final state has limited backgrounds at an e+e− collider, but at the LHC or VLHC it suffers extremely high backgrounds from standard QCD jet production. At an e+e− collider, the dominant background is tt production with fully hadronic t–quark decay in which the c–quarks fromW± decay are misidentified as b’s. Other backgrounds such as four–fermion production are negligible because of the signal is dominated by a four b final state. The results of this study are quite encouraging. Good signal–to–background was observed using event rates alone, and reconstructed Higgs mass distributions showed high–efficiency, low background regions. This note has four sections. The first is a description of the Monte Carlo generation and simulation. The second describes the analysis, including mass reconstruction and jet–flavor identification. The third presents the results, and the fourth discusses additional work to be done.
119306140
Tests of a Digital Hadron Calorimeter
In the context of developing a hadron calorimeter with extremely fine granularity for the application of Particle Flow Algorithms to the measurement of jet energies at a future lepton collider, we report on extensive tests of a small scale prototype calorimeter. The calorimeter contained up to 10 layers of Resistive Plate Chambers (RPCs) with 2560 1 \times 1 cm2 readout pads, interleaved with steel absorber plates. The tests included both long-term Cosmic Ray data taking and measurements in particle beams, where the response to broadband muons and to pions and positrons with energies in the range of 1 - 16 GeV was established. Detailed measurements of the chambers efficiency as function of beam intensity have also been performed using 120 GeV protons at varying intensity. The data are compared to simulations based on GEANT4 and to analytical calculations of the rate limitations.
124045765
Standard Model Physics at TeV2000
tev_2000 describes the collider physics program at the Fermilab Teva- tron for the next decade.
120352655
The ASTERIX spectrometer at LEAR
The ASTERIX spectrometer has been used to study the formation and the ground state of the pp atom and exclusive final states of pp annihilation at rest in a H2 gas target at NTP, using antiprotons from the Low Energy Antiproton Ring (LEAR) at CERN. The article describes the mechanical construction of the apparatus, the trigger logic, the chamber readout, and the data acquisition system. The detector calibration and the offline processing of the 55 million reconstructed events are illustrated. An overview is given about the new physics results obtained by the experiment.
18637441
Precision synchrotron radiation detectors
Precision detectors for measuring synchrotron radiation beam positions have been designed and installed as part of beam energy spectrometers at the Stanford Linear Collider (SLC). The distance between pairs of synchrotron radiation beams is measured absolutely to better than 28 mu m on a pulse-to-pulse basis, thereby contributing less than 5 MeV to the error in the measurement of SLC beam energies (approximately 50 GeV). A system of high-resolution video cameras viewing precisely aligned fiducial wire arrays overlaying phosphorescent screens has achieved this accuracy. Detectors of synchrotron radiation using the charge developed by the ejection of Compton-recoil electrons from an array of fine wires are being developed.<<ETX>>
27881414
Collider Physics at FNAL
After a three year hiatus, the Fer~ab Tevatron CoUder is back in operation defiverirrgfi coUsions at V = 1.8 TeV. The experimented situation is considerably Merent this run with an upgraded CDF detector jotied by the new DO detector. kprovements to the accelerator are expected to de~ver 100 pb1 from a run extending into 1993. Mer a description of the detectors and accelerator schedrde, recent physics restits horn the 1988-89 CDF m w~ be used to big~ght the rich physics menu at the Tevatron.
121991089
Status of BTeV: A dedicated b physics experiment at the Fermilab Tevatron Collider
BTeV is a program whose long term goal is to carry out precision studies of CP violation, mixing, and raare decays of bottom and charmed quarks in the forward direction at the Fermilab Tevatron Collider. It is planned for the new interaction region, C0, currently being constructed. We describe the technique, physics reach, and status of BTeV.
61113955
Triggering and Data Acquisition General Considerations
We provide a general introduction to trigger and data acquisition systems in High Energy Physics. We emphasize the new possibilities and new approaches that have been made possible by developments in computer technology and networking.
118563698
Hadron and photon production of heavy quarks
Recent results on the production dynamics of bottom from the Collider Detector Facility, E653, and E672 at Fermilab are reviewed and compared to previous results and theory. Agreement with theory is reasonable but the possible origins of the differences that do exist may lie in higher order corrections or possibly the shape of the gluon distribution. New results on the A‐dependence of charm are summarized. Recent results are converging towards an α parameter of 1, independent of xF. Results on inclusive charm production from Fermilab E769 and E653 and CERN WA82 are reviewed. Recent results on D−D correlations in photoproduction from E687 at Fermilab are reported. Many new results on charmed baryon states from CLEO, E687, ARGUS, and Serpukhov BIS‐2 are reviewed. This is an area where rapid progress is now occurring. Results on the D* branching fractions, Ds branching fractions, doubly Cabibbo suppressed decays, and the ratio D°→KK/D°→ππ are covered.
58032405
Distributed and/or grid-oriented approach to BTeV data analysis
Abstract The BTeV collaboration will record approximately 2 petabytes of raw data per year. It plans to analyze this data using the distributed resources of the collaboration as well as dedicated resources, primarily residing in the very large BTeV trigger farm, and resources accessible through the developing world-wide data grid. The data analysis system is being designed from the very start with this approach in mind. In particular, we plan a fully disk-based data storage system with multiple copies of the data distributed across the collaboration to provide redundancy and to optimize access. We will also position ourself to take maximum advantage of shared systems, as well as dedicated systems, at our collaborating institutions.
55388290
Prospects for heavy flavor physics at hadron colliders
The role of hadron colliders in the observation and study of CP violation in B decays is discussed. We show that hadron collider experiments can play a significant role in the early studies of these phenomena and will play an increasingly dominant role as the effort turns towards difficult to measure decays, especially those of the Bs meson, and sensitive searches for rare decays and subtle deviations from Standard Model predictions. We conclude with a discussion of the relative merits of hadron collider detectors with ‘forward’ vs ’central’ rapidity coverage.