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Related papers: Recent progress in calculation of $B_K$ using stag…

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Improved results for $B_K$ are discussed. Scaling corrections are argued to be of $O(a^2)$, leading to a reduction in the systematic error. For a kaon composed of degenerate quarks, the quenched result is ${\widehat{B}_K} = 0.825 \pm 0.027…

High Energy Physics - Lattice · Physics 2009-10-22 Stephen Sharpe

We present an update of the MILC investigation of the properties of light pseudoscalar mesons using three flavors of improved staggered quarks. Results are presented for the $\pi$ and $K$ leptonic decay constants, the CKM matrix element…

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…

We have computed $ B_K $, using two different methods with staggered fermions on a $ 16^3 \times 40 $ lattice at $ \beta = 5.7 $ with two dynamical flavors of a mass 0.01. % Using an improved wall source method, we have studied a series of…

High Energy Physics - Lattice · Physics 2009-10-28 Markus Klomfass , Weonjong Lee

We present improved results for the B and D meson spectrum from lattice QCD including the effect of u/d,s and c quarks in the sea. For the B mesons the Highly Improved Staggered Quark action is used for the sea and light valence quarks and…

High Energy Physics - Lattice · Physics 2013-05-30 R. J. Dowdall , C. T. H. Davies , T. C. Hammant , R. R. Horgan

We review recent results for B_d and B_s mixing parameters using MILC N_f=2+1 lattices, NRQCD b-quarks and AsqTad light quarks. Latest numbers for decay constants f_B and f_{B_s} are also presented. Combining our lattice results with…

High Energy Physics - Lattice · Physics 2010-11-05 J. Shigemitsu , C. T. H. Davies , E. Follana , E. Gamiz , E. Gregory , G. P. Lepage , H. Na , M. Wingate

We present a preliminary calculation of B_K using domain-wall valence quarks and 2+1 flavors of improved staggered sea quarks. Both the size of the residual quark mass, which measures the amount of chiral symmetry breaking, and of the mixed…

High Energy Physics - Lattice · Physics 2011-03-23 Christopher Aubin , Jack Laiho , Ruth S. Van de Water

We report calculations of B_K using two flavours of dynamical clover-improved Wilson lattice fermions and look for dependence on the dynamical quark mass at fixed lattice spacing. We see some evidence for dynamical quark effects. In…

High Energy Physics - Lattice · Physics 2019-08-14 J. M. Flynn , F. Mescia , A. S. B. Tariq

Using the lattice simulations in the Asqtad-improved staggered fermion formulation we compute the point-to-point $\kappa$ correlators, which are analyzed by the rooted staggered chiral perturbation theory (rS$\chi$PT). After chiral…

High Energy Physics - Lattice · Physics 2013-06-03 Ziwen Fu

We present a new determination of the B and B_s meson decay constants using NRQCD b-quarks, HISQ light and strange valence quarks and the MILC collaboration N_f=2+1 lattices. The new calculations improve on HPQCD's earlier work with NRQCD…

High Energy Physics - Lattice · Physics 2012-08-27 Heechang Na , Chris J. Monahan , Christine T. H. Davies , Ron Horgan , G. Peter Lepage , Junko Shigemitsu

We present an update of the Fermilab-MILC Collaboration's calculation of hadronic matrix elements for B^0-\bar{B^0} mixing. This work is a more extended analysis than our recent publication of the SU(3)-breaking ratio xi [arXiv:1205.7013].…

High Energy Physics - Lattice · Physics 2012-12-24 E. D. Freeland , C. M. Bouchard , C. Bernard , A. X. El-Khadra , E. Gamiz , A. S. Kronfeld , J. Laiho , R. S. Van de Water

We report the final results of the ALPHA collaboration for some B-physics observables: $f_B$, $f_{B_s}$ and $m_b$. We employ CLS configurations with 2 flavors of $O(a)$ improved Wilson fermions in the sea and pion masses ranging down to 190…

High Energy Physics - Lattice · Physics 2013-09-05 F. Bernardoni , B. Blossier , J. Bulava , M. Della Morte , P. Fritzsch , N. Garron , A. Gerardin , J. Heitger , G. von Hippel , H. Simma , R. Sommer

We present determinations of the B meson decay constant f_B and of the ratio f_{B_s}/f_B using the MILC collaboration unquenched gauge configurations which include three flavors of light sea quarks. The mass of one of the sea quarks is kept…

We calculate the fermion self-energy at O(alpha_s) for the Symanzik improved staggered fermion action used in recent lattice simulations by the MILC collaboration. We demonstrate that the algebraic approach to lattice perturbation theory,…

High Energy Physics - Lattice · Physics 2009-11-10 Thomas Becher , Kirill Melnikov

Using the MILC 2+1 flavor asqtad quark action ensembles, we are calculating the form factors $f_0$ and $f_+$ for the semileptonic $B_s \rightarrow K \ell\nu$ decay. A total of six ensembles with lattice spacing from $\approx0.12$ to 0.06 fm…

We introduce an alternative discretization for static quarks on the lattice retaining the O(a) improvement properties of the Eichten-Hill action. In this formulation, statistical fluctuations are reduced by a factor which grows…

High Energy Physics - Lattice · Physics 2008-11-26 M. Della Morte , S. Durr , J. Heitger , H. Molke , J. Rolf , A. Shindler , R. Sommer

The MILC Collaboration has been producing ensembles of lattice configurations with three dynamical flavors for the past few years. There are now results for three lattice spacings for a variety of light and strange quark masses, ranging…

High Energy Physics - Lattice · Physics 2009-11-10 Steven Gottlieb

Calculations of B leptonic decays and B- bar B mixing using NRQCD heavy and Asqtad light valence quarks on the MILC dynamical configurations are described. Smearing has been implemented to substantially reduce the statistical errors of the…

High Energy Physics - Lattice · Physics 2009-11-10 A. Gray , C. Davies , E. Gulez , G. P. Lepage , J. Shigemitsu , M. Wingate

We present progress on an ongoing calculation of the $B_s\to D_s^{(*)} l \nu$ form factors calculated on the $n_f=2+1+1$ MILC ensembles and using the Highly Improved Staggered Quark action for all valence quarks. We perform the calculation…

High Energy Physics - Lattice · Physics 2019-01-16 E. McLean , C. T. H. Davies , A. T. Lytle , J. Koponen

We present a study of the $D$ and $B$ leptonic decay constants on the MILC $N_f=2+1$ asqtad gauge ensembles using asqtad-improved staggered light quarks and clover heavy quarks in the Fermilab interpretation. Our previous analysis…