1,620 research outputs found

    Top Spin and Experimental Tests

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    We examine pair mass dependence near threshold as a means to measure the spin of the top quark in hadron collisions, and we discuss the possibility that a top squark signal could be hidden among the top events.Comment: 9 pages, RevTeX, 3 figures. Contribution to the Thinkshop on Top-Quark Physics for the Tevatron Run II, Fermilab, October 16 - 18, 199

    Forecasting volatility and value at risk of an Islamic tangency portfolio

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    Academic literature arrives at diverse conclusions about the volatility forecasting accuracy of GARCH and EWMA models. Most studies analyse conventional equities, not focusing on shariah-compliant investing and the Islamic community. In this study, GARCH and EWMA models under different distributional assumptions were used to evaluate the one-step-ahead volatility and VaR forecasting accuracy for an Islamic Tangency Portfolio. Analysis confirms findings by Ding & Meade(2010) and shows that EWMA also outperforms GARCH(1,1) models for a sharia-compliant portfolio under short selling restrictions, while indicating the lowest failure rate of actual losses exceeding predicted VaR estimates

    SUSY Production Cross Sections

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    We summarize the status of next-to-leading order perturbative quantum chromodynamics (pQCD) calculations of the cross sections for the production of squarks, gluinos, neutralinos, charginos, and sleptons as a function of the produced sparticle masses in proton-antiproton collisions at the hadronic center-of-mass energy 2 TeV.Comment: 7 pages, latex, plus one .eps figure; subgroup summary for the SUGRA working group of the Fermilab workshop Physics at Run II -- Supersymmetry/Higg

    Predictions for associated production of gauginos and gluinos at NLO in SUSY-QCD

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    NLO SUSY-QCD contributions to associated production of gluinos and gauginos are shown to enhance the cross sections by about 10% at the Tevatron and by as much as a factor of two at the LHC. They shift the mass determinations or discovery limits, soften the pTp_T spectra, and stabilize the predictions against variations of the renormalization and factorization scales.Comment: 4 pages, Latex (uses Moriond style file), 8 eps-figures. Talk presented at the XXXVth Rencontres de Moriond, QCD and High Energy Hadronic Interactions, Les Arcs, France, March 18-25, 200

    Next-to-Leading Order SUSY-QCD Predictions for Associated Production of Gauginos and Gluinos

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    We present complete results of a next-to-leading order calculation of the production of gaugino-like charginos (\chargino) and neutralinos (\neutralino) in association with gluinos (\gluino) at hadron colliders, including the strong corrections from the exchange of colored particles and sparticles. Adopting a variety of models for the sparticle mass spectrum, including typical supergravity (SUGRA) models and a light gluino model, we provide predictions for total and differential cross sections at the energies of the Fermilab Tevatron and CERN Large Hadron Collider (LHC).Comment: 91 pages, Latex, including 26 figure

    Erratum: Next-to-leading order supersymmetric QCD predictions for associated production of gauginos and gluinos [Phys. Rev. D 62, 095014 (2000)]

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    Errors in the published version of the paper are corrected, and new figures are provided.Comment: 3 pages, latex, 4 figure

    Completing Queries: Rewriting of IncompleteWeb Queries under Schema Constraints

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    Reactive Web systems, Web services, and Web-based publish/ subscribe systems communicate events as XML messages, and in many cases require composite event detection: it is not sufficient to react to single event messages, but events have to be considered in relation to other events that are received over time. Emphasizing language design and formal semantics, we describe the rule-based query language XChangeEQ for detecting composite events. XChangeEQ is designed to completely cover and integrate the four complementary querying dimensions: event data, event composition, temporal relationships, and event accumulation. Semantics are provided as model and fixpoint theories; while this is an established approach for rule languages, it has not been applied for event queries before

    Identification of Design Principles

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    This report identifies those design principles for a (possibly new) query and transformation language for the Web supporting inference that are considered essential. Based upon these design principles an initial strawman is selected. Scenarios for querying the Semantic Web illustrate the design principles and their reflection in the initial strawman, i.e., a first draft of the query language to be designed and implemented by the REWERSE working group I4

    Effective and Efficient Data Access in the Versatile Web Query Language Xcerpt

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    Access to Web data has become an integral part of many applications and services. In the past, such data has usually been accessed through human-tailoredHTMLinterfaces.Nowadays, rich client interfaces in desktop applications or, increasingly, in browser-based clients ease data access and allow more complex client processing based on XML or RDF data retrieved throughWeb service interfaces. Convenient specifications of the data processing on the client and flexible, expressive service interfaces for data access become essential in this context.Web query languages such as XQuery, XSLT, SPARQL, or Xcerpt have been tailored specifically for such a setting: declarative and efficient access and processing ofWeb data. Xcerpt stands apart among these languages by its versatility, i.e., its ability to access not just oneWeb format but many. In this demonstration, two aspects of Xcerpt are illustrated in detail: The first part of the demonstration focuses on Xcerpt’s pattern matching constructs and rules to enable effective and versatile data access. It uses a concrete practical use case from bibliography management to illustrate these language features. Xcerpt’s visual companion language visXcerpt is used to provide an intuitive interface to both data and queries. The second part of the demonstration shows recent advancements in Xcerpt’s implementation focusing on experimental evaluation of recent complexity results and optimization techniques, as well as scalability over a number of usage scenarios and input sizes
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