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Related papers: $f_B$ and $f_{B_s}$ using NRQCD

200 papers

We present an unquenched lattice calculation for the $B^0-\bar{B}^0$ transition amplitude. The calculation, carried out at an inverse lattice spacing $1/a$ = 2.22(4) GeV, incorporates two flavors of dynamical quarks described by the fully…

We match the continuum and lattice axial vector and vector currents at one loop in perturbation theory. For the heavy quarks we use the nonrelativistic QCD (NRQCD) action and for the light quarks the Highly Improved Staggered Quark (HISQ)…

High Energy Physics - Lattice · Physics 2013-04-18 Christopher Monahan , Junko Shigemitsu , Ron Horgan

We present results on the spectrum of B mesons and heavy baryons, using a non-relativistic formulation for the heavy and a clover action for the light quark. We also discuss B meson decay constants and their dependency upon the heavy meson…

High Energy Physics - Lattice · Physics 2010-01-18 A. Ali Khan , S. Collins , C. Davies , J. Shigemitsu , J. Sloan

We extend our previous studies to calculate the B meson B parameters B_B and B_S on the lattice, and present an update of the results for the B_s meson width difference. We perform an extensive study of systematic errors in the quenched…

High Energy Physics - Phenomenology · Physics 2016-11-23 Shoji Hashimoto , Norikazu Yamada

Decoupling of c-quark loops in b-quark HQET is considered. The decoupling coefficients for the HQET heavy-quark field and the heavy-light quark current are calculated with the three-loop accuracy. The last result can be used to improve the…

High Energy Physics - Phenomenology · Physics 2009-11-11 A. G. Grozin , A. V. Smirnov , V. A. Smirnov

Results for $f_B$, $f_{B_s}$, $f_D$, $f_{D_s}$, and their ratios are presented. High statistics quenched runs at $\beta=5.7$, $5.85$, $6.0$, and $6.3$, plus a run still in progress at $\beta=6.52$ make possible a preliminary extrapolation…

We present preliminary results for $B_K$ calculated using improved staggered fermions with a mixed action (HYP-smeared staggered valence quarks and AsqTad staggered sea quarks). We investigate the effect of non-degenerate quarks on $B_K$…

High Energy Physics - Lattice · Physics 2008-11-26 Jongjeong Kim , Taegil Bae , Weonjong Lee , Stephen R. Sharpe

We present results for pseudoscalar decay constants of heavy-light mesons using both quenched and N_f = 2 dynamical fermion configurations. A variety of fermion actions is investigated : Wilson, nonperturbative clover, and fat-link clover.…

High Energy Physics - Lattice · Physics 2008-11-26 C. Bernard , S. Datta , C. DeTar , S. Gottlieb , U. M. Heller , J. Hetrick , C. Mcneile , K. Orginos , R. Sugar , D. Toussaint

We present results for the B_s meson decay constant f_{B_s} from simulations at three lattice spacings in the range a^{-1}=1.1 to 2.6 GeV using NRQCD heavy quarks and clover light quarks in the quenched approximation. We study scaling of…

High Energy Physics - Lattice · Physics 2010-01-18 S. Collins , C. T. H. Davies , J. Hein , G. P. Lepage , C. J. Morningstar , J. Shigemitsu , J. Sloan

We report our final estimate of the b-quark mass from $N_f=2$ lattice QCD simulations using Heavy Quark Effective Theory non-perturbatively matched to QCD at $O(1/m_h)$. Treating systematic and statistical errors in a conservative manner,…

High Energy Physics - Lattice · Physics 2014-02-05 F. Bernardoni , B. Blossier , J. Bulava , M. Della Morte , P. Fritzsch , N. Garron , A. Gerardin , J. Heitger , G. von Hippel , H. Simma , R. Sommer

Partially quenched theories are theories in which the valence- and sea-quark masses are different. In this paper we calculate the nonanalytic one-loop corrections of some physical quantities: the chiral condensate, weak decay constants,…

High Energy Physics - Lattice · Physics 2008-11-26 Maarten Golterman , Ka Chun Leung

We present a lattice investigation of the heavy-light meson decay constants using Wilson light quarks and NRQCD heavy quarks, partially including the effects of dynamical sea quarks. We calculate the pseudoscalar and vector decay constants…

High Energy Physics - Lattice · Physics 2010-01-18 S. Collins , U. M. Heller , J. Sloan , J. Shigemitsu , A. Ali Khan , C. T. H. Davies

We match continuum and lattice heavy-light four-fermion operators at one loop in perturbation theory. For the heavy quarks we use nonrelativistic QCD and for the massless light quarks the highly improved staggered quark action. We include…

High Energy Physics - Lattice · Physics 2014-10-02 Christopher Monahan , Elvira Gamiz , Ron Horgan , Junko Shigemitsu

We construct an improved version of nonrelativistic QCD for use in lattice simulations of heavy quark physics, with the goal of reducing systematic errors from all sources to below 10\%. We develop power counting rules to assess the…

High Energy Physics - Lattice · Physics 2010-11-01 G. P. Lepage , L. Magnea , C. Nakhleh , U. Magnea , K. Hornbostel

We demonstrate the viability of improved staggered light quarks in studies of heavy-light systems. Our method for constructing heavy-light operators exploits the close relation between naive and staggered fermions. The new approach is…

High Energy Physics - Lattice · Physics 2009-11-07 Matthew Wingate , Junko Shigemitsu , Christine T. H. Davies , G. Peter Lepage , Howard D. Trottier

We present results on an analysis of the decay constants f_B and f_Bs with two flavours of sea quark. The calculation has been carried out on 3 different bare gauge couplings and 4 sea quark masses at each gauge coupling, with m_pi/m_rho…

We present further results for one-loop matching of heavy-light axial and vector currents between continuum QCD and a lattice theory with NRQCD heavy quarks and massless clover quarks.

High Energy Physics - Lattice · Physics 2009-10-31 Colin J. Morningstar , Junko Shigemitsu

We have calculated the decay constants of B and $D$ mesons with lattice QCD. We use an $O(a)$ improved action that takes light quark actions as a starting point, tuned so that it can be directly applied at the physical masses of the $b$ and…

High Energy Physics - Phenomenology · Physics 2010-11-19 Aida X. El-Khadra , Andreas S. Kronfeld , Paul B. Mackenzie , Sinead M. Ryan , James N. Simone

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 present a progress report on new calculations of B and B_s meson decay constants employing NRQCD heavy and HISQ light valence quarks and using MILC N_f = 2+1 AsqTad lattices. Bare quark masses have been retuned in accord with HPQCD's new…

High Energy Physics - Lattice · Physics 2011-10-27 Junko Shigemitsu , Heechang Na , Christine Davies , Ron Horgan , Chris Monahan , Peter Lepage