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Title: Improved staggered eigenvalues in SU(2)

Abstract

We study the low-lying modes of staggered Dirac operators for quenched SU(2) and show that improvement changes the distribution from lattice-like to continuum-like at lattice spacings a = 0.07 - 0.10 fm, which are representative of current dynamical SU(3) simulations.

Authors:
;  [1];  [2]
  1. SUPA, Department of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ (United Kingdom)
  2. SUPA, School of Physics, University of Edinburgh, King's Buildings, Edinburgh EH9 3JZ (United Kingdom)
Publication Date:
OSTI Identifier:
21056903
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Conference Proceedings; Journal Volume: 892; Journal Issue: 1; Conference: QCHS7: 7. conference on quark confinement and the hadron spectrum, Ponta Delgada, Acores (Portugal), 2-7 Sep 2006; Other Information: DOI: 10.1063/1.2714462; (c) 2007 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; COMPUTERIZED SIMULATION; DIRAC EQUATION; DIRAC OPERATORS; DISTRIBUTION; EIGENVALUES; LATTICE FIELD THEORY; QUANTUM CHROMODYNAMICS; SU-2 GROUPS; SU-3 GROUPS

Citation Formats

Follana, E., Davies, C. T. H., and Hart, A.. Improved staggered eigenvalues in SU(2). United States: N. p., 2007. Web. doi:10.1063/1.2714462.
Follana, E., Davies, C. T. H., & Hart, A.. Improved staggered eigenvalues in SU(2). United States. doi:10.1063/1.2714462.
Follana, E., Davies, C. T. H., and Hart, A.. Tue . "Improved staggered eigenvalues in SU(2)". United States. doi:10.1063/1.2714462.
@article{osti_21056903,
title = {Improved staggered eigenvalues in SU(2)},
author = {Follana, E. and Davies, C. T. H. and Hart, A.},
abstractNote = {We study the low-lying modes of staggered Dirac operators for quenched SU(2) and show that improvement changes the distribution from lattice-like to continuum-like at lattice spacings a = 0.07 - 0.10 fm, which are representative of current dynamical SU(3) simulations.},
doi = {10.1063/1.2714462},
journal = {AIP Conference Proceedings},
number = 1,
volume = 892,
place = {United States},
year = {Tue Feb 27 00:00:00 EST 2007},
month = {Tue Feb 27 00:00:00 EST 2007}
}
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  • We compute O({alpha}{sub s}) lattice-to-continuum perturbative matching coefficients for the {delta}S=2 flavor changing four-quark operators for the Asqtad improved staggered action. In conjunction with lattice simulations with three flavors of light, dynamical quarks, our results yield an unquenched determination of B{sub K}, the parameter that determines the amount of indirect CP violation in the neutral kaon system. Its value is an important input for the unitarity triangle analysis of weak decays.
  • We report results for the interaction measure, pressure, and energy density for nonzero-temperature QCD with 2+1 flavors of improved staggered quarks. In our simulations, we use a Symanzik improved gauge action and the Asqtad O(a{sup 2}) improved staggered quark action for lattices with temporal extent N{sub t}=4 and 6. The heavy quark mass m{sub s} is fixed at approximately the physical strange quark mass and the two degenerate light quarks have masses m{sub ud}{approx_equal}0.1m{sub s} or 0.2m{sub s}. The calculation of the thermodynamic observables employs the integral method where energy density and pressure are obtained by integration over the interactionmore » measure.« less
  • Dramatic progress has been made over the last decade in the numerical study of quantum chromodynamics (QCD) through the use of improved formulations of QCD on the lattice (improved actions), the development of new algorithms, and the rapid increase in computing power available to lattice gauge theorists. In this article simulations of full QCD are described using the improved staggered quark formalism, ''asqtad'' fermions. These simulations were carried out with two degenerate flavors of light quarks (up and down) and with one heavier flavor, the strange quark. Several light quark masses, down to about three times the physical light quarkmore » mass, and six lattice spacings have been used. These enable controlled continuum and chiral extrapolations of many low energy QCD observables. The improved staggered formalism is reviewed, emphasizing both advantages and drawbacks. In particular, the procedure for removing unwanted staggered species in the continuum limit is reviewed. Then the asqtad lattice ensembles created by the MILC Collaboration are described. All MILC lattice ensembles are publicly available, and they have been used extensively by a number of lattice gauge theory groups. The physics results obtained with them are reviewed, and the impact of these results on phenomenology is discussed. Topics include the heavy quark potential, spectrum of light hadrons, quark masses, decay constants of light and heavy-light pseudoscalar mesons, semileptonic form factors, nucleon structure, scattering lengths, and more.« less