1,620 research outputs found
Top Spin and Experimental Tests
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
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
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
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 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
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)]
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
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
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
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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