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Related papers: Lambda_msbar from the static potential for QCD wit…

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We report on a scaling test of several mesonic observables in the non-perturbatively O(a) improved Wilson theory with two flavors of dynamical quarks. The observables are constructed in a fixed volume of 2.4fm x (1.8fm)^3 with Schroedinger…

High Energy Physics - Lattice · Physics 2008-11-26 Michele Della Morte , Patrick Fritzsch , Harvey B. Meyer , Hubert Simma , Rainer Sommer , Shinji Takeda , Oliver Witzel , Ulli Wolff

Three-flavor lattice QCD simulations and two-loop perturbation theory are used to make the most precise determination to date of the strange-, up-, and down-quark masses, $m_s$, $m_u$, and $m_d$, respectively. Perturbative matching is…

High Energy Physics - Phenomenology · Physics 2008-11-26 Quentin Mason , Howard D. Trottier , Ron Horgan , Christine T. H. Davies , G. Peter Lepage

We present a new determination of the QCD strong coupling constant based on precise lattice calculations of the $\Upsilon$ spectrum. The largest systematic uncertainty in previous such determinations resulted from the absence of vacuum…

High Energy Physics - Phenomenology · Physics 2009-10-28 C. T. H. Davies , K. Hornbostel , G. P. Lepage , A. Lidsey , J. Shigemitsu , J. Sloan

We pursue a new method, based on lattice QCD, for determining the quantities $\bar{\Lambda}$, $\lambda_1$, and $\lambda_2$ of heavy-quark effective theory. We combine Monte Carlo data for the meson mass spectrum with perturbative…

High Energy Physics - Phenomenology · Physics 2009-10-31 Andreas S. Kronfeld , James N. Simone

We compute pseudoscalar meson masses and decay constants in partially quenched QCD with three dynamical flavors of improved staggered quarks. Fitting the lattice data to staggered chiral perturbation theory forms and extrapolating in quark…

We present results for the light quark masses and the neutral kaon mixing parameter $B_K$ from lattice QCD. Our data set includes lighter than physical light quark masses and 5 lattice spacings so that chiral extrapolation is not necessary…

High Energy Physics - Phenomenology · Physics 2012-07-02 Christian Hoelbling

The leading non-perturbative contribution to the static QCD potential at r << 1/Lambda_QCD is known to be O(r^2) in operator-product expansion. It indicates that a "Coulomb+linear" potential at r <~ 1/Lambda_QCD is included in the…

High Energy Physics - Phenomenology · Physics 2007-05-23 Y. Sumino

We determine the leptonic decay constants in three flavor unquenched lattice QCD. We use O(a^2)-improved staggered light quarks and O(a)-improved charm quarks in the Fermilab heavy quark formalism. Our preliminary results, based upon an…

We present O(g^4) calculations of both planar and non-planar Wilson loops for various actions in the presence of sea quarks. In particular, the plaquette, the static potential and the static self energy are calculated to this order for…

High Energy Physics - Lattice · Physics 2007-05-23 Gunnar S. Bali , Peter Boyle

We report results on the static quark potential in two-flavor full QCD. The calculation is performed for three values of lattice spacing $a^{-1}\approx 0.9, 1.3$ and 2.5 GeV on $12^3{\times}24, 16^3{\times}32$ and $24^3{\times}48$ lattices…

We use the recently obtained theoretical expression for the complete QCD static energy at next-to-next-to-next-to leading-logarithmic accuracy to determine r_0Lambda_MS by comparison with available lattice data, where r_0 is the lattice…

High Energy Physics - Phenomenology · Physics 2012-06-28 Nora Brambilla , Xavier Garcia i Tormo , Joan Soto , Antonio Vairo

We present a new determination of the strong coupling constant from lattice QCD simulations. We use four different short-distance quantities to obtain the coupling, three different (infrared) meson splittings to tune the simulation…

High Energy Physics - Lattice · Physics 2016-08-24 C. T. H. Davies , K. Hornbostel , G. P. Lepage , P. McCallum , J. Shigemitsu , J. Sloan

We present a high statistics study of the light hadron spectrum and quark masses in QCD with two flavors of dynamical quarks. Numerical simulations are carried out using the plaquette gauge action and the O(a)-improved Wilson quark action…

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…

High Energy Physics - Lattice · Physics 2009-09-29 MILC Collaboration , C. Aubin , C. Bernard , C. DeTar , Steven Gottlieb , E. B. Gregory , U. M. Heller , J. E. Hetrick , J. Osborn , R. Sugar , D. Toussaint

We study the effects of dynamical quarks on the static quark potential at distances shorter than those where string breaking is expected. Quenched calculations and calculations with three flavors of dynamical quarks are done on sets of…

High Energy Physics - Lattice · Physics 2009-10-31 C. Bernard , T. Burch , K. Orginos , D. Toussaint , T. A. DeGrand , C. E. DeTar , S. Gottlieb , U. M. Heller , J. E. Hetrick , R. L. Sugar

We present results for light quark masses from a systematic lattice QCD study with two degenerate flavors of dynamical quarks. Simulations are made with a renormalization-group improved gauge action and a mean-field improved clover quark…

The eigenvalue spectrum $\rho(\lambda)$ of the Dirac operator is numerically calculated in lattice QCD with 2+1 flavors of dynamical domain-wall fermions. In the high-energy regime, the discretization effects become significant. We subtract…

High Energy Physics - Lattice · Physics 2018-07-11 Katsumasa Nakayama , Hidenori Fukaya , Shoji Hashimoto

Capitalizing on recent advances in lattice QCD, we present a calculation of the leptonic decay constants f_{B_s} and f_{D_s} that includes effects of one strange sea quark and two light sea quarks. The discretization errors of improved…

High Energy Physics - Phenomenology · Physics 2011-01-27 Matthew Wingate , Christine T. H. Davies , Alan Gray , G. Peter Lepage , Junko Shigemitsu

We present results by the ALPHA collaboration for the $\Lambda$-parameter in 3-flavour QCD and the strong coupling constant at the electroweak scale, $\alpha_s(m_Z)$, in terms of hadronic quantities computed on the CLS gauge configurations.…

High Energy Physics - Lattice · Physics 2017-01-13 M. Bruno , M. Dalla Brida , P. Fritzsch , T. Korzec , A. Ramos , S. Schaefer , H. Simma , S. Sint , R. Sommer

We argue that high-precision lattice QCD is now possible, for the first time, because of a new improved staggered quark discretization. We compare a wide variety of nonperturbative calculations in QCD with experiment, and find agreement to…