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Full-Text Articles in Physics
Light Hadrons With Improved Staggered Quarks: Approaching The Continuum Limit, James E. Hetrick, C. Aubin
Light Hadrons With Improved Staggered Quarks: Approaching The Continuum Limit, James E. Hetrick, C. Aubin
All Faculty Articles - School of Engineering and Computer Science
We have extended our program of QCD simulations with an improved Kogut-Susskind quark action to a smaller lattice spacing, approximately 0.09 fm. Also, the simulations with a ≈ 0.12 fm have been extended to smaller quark masses. In this paper we describe the new simulations and computations of the static quark potential and light hadron spectrum. These results give information about the remaining dependences on the lattice spacing. We examine the dependence of computed quantities on the spatial size of the lattice, on the numerical precision in the computations, and on the step size used in the numerical integrations. We …
Light Pseudoscalar Decay Constants, Quark Masses, And Low Energy Constants From Three Flavor Lattice Qcd, James E. Hetrick, C. Aubin
Light Pseudoscalar Decay Constants, Quark Masses, And Low Energy Constants From Three Flavor Lattice Qcd, James E. Hetrick, C. Aubin
All Faculty Articles - School of Engineering and Computer Science
As part of our program of lattice simulations of three-flavor QCD with improved staggered quarks, we have calculated pseudoscalar meson masses and decay constants for a range of valence quark masses and sea-quark masses on lattices with lattice spacings of about 0.125 and 0.09 fm. We fit the lattice data to forms computed with “staggered chiral perturbation theory.” Our results provide a sensitive test of the lattice simulations, and especially of the chiral behavior, including the effects of chiral logarithms. We find: fπ = 129.5 ± 0.9 ± 3.5 MeV, fK = 156.6 ± 1.0 ± 3.6 MeV, and fK/ …
High-Precision Lattice Qcd Confronts Experiment, James E. Hetrick, C. T. Davies
High-Precision Lattice Qcd Confronts Experiment, James E. Hetrick, C. T. Davies
All Faculty Articles - School of Engineering and Computer Science
The recently developed Symanzik-improved staggered-quark discretization allows unquenched lattice-QCD simulations with much smaller (and more realistic) quark masses than previously possible. To test this formalism, we compare experiment with a variety of nonperturbative calculations in QCD drawn from a restricted set of “gold-plated” quantities. We find agreement to within statistical and systematic errors of 3% or less. We discuss the implications for phenomenology and, in particular, for heavy-quark physics.
First Determination Of The Strange And Light Quark Masses From Full Lattice Qcd, James E. Hetrick, C. Aubin
First Determination Of The Strange And Light Quark Masses From Full Lattice Qcd, James E. Hetrick, C. Aubin
All Faculty Articles - School of Engineering and Computer Science
We compute the strange quark mass ms and the average of the u and d quark masses m̂ using full lattice QCD with three dynamical quarks combined with experimental values for the pion and kaon masses. The simulations have degenerate u and d quarks with masses mu=md≡m̂ as low as ms/8, and two different values of the lattice spacing. The bare lattice quark masses obtained are converted to the $\msbar$ scheme using perturbation theory at O(alphas). Our results are: $m_s^\msbar$(2 GeV) = 76(0)(3)(7)(0) MeV, $\hat m^\msbar$(2 GeV) = 2.8(0)(1)(3)(0) MeV and ms/m̂ = 27.4(1)(4)(0)(1), where the errors are from statistics, …