2,341 research outputs found
The CKM Matrix from Lattice QCD
Lattice QCD plays an essential role in testing and determining the parameters
of the CKM theory of flavor mixing and CP violation. Very high precisions are
required for lattice calculations analysing CKM data; I discuss the prospects
for achieving them. Lattice calculations will also play a role in investigating
flavor mixing and CP violation beyond the Standard Model.Comment: To appear in Prog. Theor. Phys. Vol. 122, No.1 (Special Issue
Progress in QCD Using Lattice Gauge Theory
Review of results from lattice QCD of relevance to standard-model
phenomenology, to appear in Annual Review of Nuclear and Particle Science. KEY
WORDS: hadron masses, quark mixing (CKM) matrix, weak matrix elements, strong
coupling constant.Comment: 41 pages LaTeX, FERMILAB-PUB-93/058-T. Figures and style file are
uuencoded and appended. Figures embedded with epsf.sty, available from the
serve
Metamodelling of multivariable engine models for real-time flight simulation.
Sophisticated real-time distributed flight simulation environments may be constructed from a wide range of modelling and simulation tools. In this way accuracy, detail and model flexibility may be incorporated into the simulator. Distributed components may be constructed by a wide range of methods, from high level environments such as Matlab, through coded environments such as C or Fortran to hardware-in-the- loop. In this paper the Response Surface Methodology is combined with a hyper-heuristic (evolutionary algorithm) and applied to the representation of computationally intensive non-linear multivariable engine modelling. The paper investigates the potential for metamodelling (models of models) dynamic models which were previously too slow to be included in multi-component, high resolution real-time simulation environments. A multi-dimensional gas turbine model with five primary control inputs, six environmental inputs and eleven outputs is considered. An investigation has been conducted to ascertain to what extent these systems can be approximated by response surfaces with experiments which have been designed by hyper-heuristics as a first step towards automatic modelling methodology
Expected Precision of Higgs Boson Partial Widths within the Standard Model
We discuss the sources of uncertainty in calculations of the partial widths
of the Higgs boson within the Standard Model. The uncertainties come from two
sources: the truncation of perturbation theory and the uncertainties in input
parameters. We review the current status of perturbative calculations and note
that these are already reaching the parts-per-mil level of accuracy for the
major decay modes. The main sources of uncertainty will then come from the
parametric dependences on alpha_s, m_b, and m_c. Knowledge of these parameters
is systematically improvable through lattice gauge theory calculations. We
estimate the precision that lattice QCD will achieve in the next decade and the
corresponding precision of the Standard Model predictions for Higgs boson
partial widths.Comment: 20 pages, 1 figure; v2: minor typo correction
Nonperturbative ``Lattice Perturbation Theory''
We discuss a program for replacing standard perturbative methods with Monte
Carlo simulations in short distance lattice gauge theory calculations.Comment: 3 pages, uuencoded Latex file, two embedded figures and .sty file
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The cost of youth homelessness in Australia study: snapshot report 1
Overview: This is the first national Australian longitudinal study investigating the economic, personal and social costs of youth homelessness over time across a broad range of locations.
Too many young Australians are without any form of safe and secure accommodation. It is estimated that approximately 44,000 Australians under the age of 25 are homeless, but the actual number is likely to be higher. Homeless young people comprise some 42 per cent of the Australian homeless population.
Participants have been tracked by researchers over a three year period to see what kind of issues young homeless people face: changes in their circumstances, health and quality of life; how many used services; the types of services they accessed; and whether or not they transitioned from homelessness to permanent accommodation
Lattice QCD Application Development within the US DOE Exascale Computing Project
In October, 2016, the US Department of Energy launched the Exascale Computing
Project, which aims to deploy exascale computing resources for science and
engineering in the early 2020's. The project brings together application teams,
software developers, and hardware vendors in order to realize this goal.
Lattice QCD is one of the applications. Members of the US lattice gauge theory
community with significant collaborators abroad are developing algorithms and
software for exascale lattice QCD calculations. We give a short description of
the project, our activities, and our plans.Comment: 35th International Symposium on Lattice Field Theory (Lattice 2017
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