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A lattice QCD calculation of the B meson decay constant is presented. In order to investigate the scaling violation associated with the heavy quark, parallel simulations are carried out employing both Wilson and the O(a)-improved clover…

High Energy Physics - Lattice · Physics 2007-05-23 JLQCD collaboration , S. Aoki , M. Fukugita , S. Hashimoto , N. Ishizuka , Y. Iwasaki , K. Kanaya , Y. Kuramashi , M. Okawa , A. Ukawa , T. Yoshié

We present a progress report on our calculation of the decay constants $f_B$ and $f_{B_s}$ from lattice-QCD simulations with highly-improved staggered quarks. Simulations are carried out with several heavy valence-quark masses on…

Ordinary matter is described by six fundamental parameters: three couplings (gravitational, electromagnetic and strong) and three masses: the electron's (m_e) and those of the up (m_u) and down (m_d) quarks. An additional mass enters…

High Energy Physics - Lattice · Physics 2011-06-29 S. Durr , Z. Fodor , C. Hoelbling , S. D. Katz , S. Krieg , T. Kurth , L. Lellouch , T. Lippert , K. K. Szabo , G. Vulvert

We present precision lattice calculations of the pseudoscalar decay constants of the charmed sector as well as determinations of the bottom quark mass and its ratio to the charm quark mass. We employ Nf=2+1+1 dynamical quark gauge…

High Energy Physics - Lattice · Physics 2014-11-04 A. Bussone , N. Carrasco , P. Dimopoulos , R. Frezzotti , P. Lami , V. Lubicz , F. Nazzaro , E. Picca , L. Riggio , G. C. Rossi , F. Sanfilippo , S. Simula , C. Tarantino

The correlator of heavy-quark currents is calculated in quenched Lattice QCD on a $16^3 \times 32$-lattice for $\beta= { 6, 6.3 }$. The renormalized charmed quark mass is extracted from the short-distance part of that correlator:…

High Energy Physics - Lattice · Physics 2016-09-01 A. Bochkarev , Ph. de Forcrand

We determine the strong coupling alpha_s at NNLO in perturbative QCD using the global dataset input to the NNPDF2.1 NNLO parton fit: data from neutral and charged current deep-inelastic scattering, Drell-Yan, vector boson production and…

High Energy Physics - Phenomenology · Physics 2015-05-30 Richard D. Ball , Valerio Bertone , Luigi Del Debbio , Stefano Forte , Alberto Guffanti , Jose I. Latorre , Simone Lionetti , Juan Rojo , Maria Ubiali

We extract the value of the strong coupling constant alpha_s from a single-parameter pointlike fit to the photon structure function F_2^gamma at large x and Q^2 and from a first five-parameter full (pointlike and hadronic) fit to the…

High Energy Physics - Phenomenology · Physics 2009-11-07 S. Albino , M. Klasen , S. Soldner-Rembold

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 study the use of the complex-Langevin equation (CLE) to simulate lattice QCD at a finite chemical potential ($\mu$) for quark-number, which has a complex fermion determinant that prevents the use of standard simulation methods based on…

High Energy Physics - Lattice · Physics 2019-10-02 J. B. Kogut , D. K. Sinclair

In this paper we show that the apparent failure of QCD lattice perturbation theory to account for Monte Carlo measurements of perturbative quantities results from choosing the bare lattice coupling constant as the expansion parameter. Using…

High Energy Physics - Lattice · Physics 2009-10-22 G. P. Lepage , P. B. Mackenzie

We determine the strong coupling $\alpha_s(m_Z)$ from dimensionless ratios of roots of moments of the charm- and bottom-quark vector and charm pseudo-scalar correlators, dubbed…

High Energy Physics - Phenomenology · Physics 2020-04-22 Diogo Boito , Vicent Mateu

We provide a 0.8\%-accurate determination of $V_{cs}$ from combining experimental results for the differential rate of $D \rightarrow K$ semileptonic decays with precise form factors that we determine from lattice QCD. This is the first…

High Energy Physics - Lattice · Physics 2021-09-01 Bipasha Chakraborty , W. G. Parrott , C. Bouchard , C. T. H. Davies , J. Koponen , G. P. Lepage

We perform pQCD analysis of the existing DIS data for charged leptons with account of corrections up to the NNLO. The parton distributions, value of strong coupling constant, and high-twist terms are extracted and their stability with…

High Energy Physics - Phenomenology · Physics 2013-05-29 Alekhin Sergey

The QCD-coupling is a necessary input in the computation of many observables, and the parametric error on input parameters can be a dominant source of uncertainty. The coupling can be extracted by comparing high order perturbative…

High Energy Physics - Lattice · Physics 2022-03-16 Leonardo Chimirri , Rainer Sommer

The QCD coupling appears in the perturbative expansion of the current-current two-point (vacuum polarization) function. Any lattice calculation of vacuum polarization is plagued by several competing non-perturbative effects at small momenta…

High Energy Physics - Lattice · Physics 2015-10-19 Renwick J. Hudspith , Randy Lewis , Kim Maltman , Eigo Shintani

I review the determination of the strong coupling constant from moments of quarkonium correlators calculated on the lattice. I discuss different sources of systematic errors in such calculations.

High Energy Physics - Lattice · Physics 2019-03-18 Peter Petreczky

We demonstrate that lattice QCD calculations can be made $10^3$--$10^6$ times faster by using very coarse lattices. To obtain accurate results, we replace the standard lattice actions by perturbatively-improved actions with tadpole-improved…

High Energy Physics - Lattice · Physics 2009-10-28 M. Alford , W. Dimm , G. P. Lepage , G. Hockney , P. B. Mackenzie

We present the computation of invariants that arise in the strong coupling expansion of lattice QCD. These invariants are needed for Monte Carlo simulations of Lattice QCD with staggered fermions in a dual, color singlet representation.…

High Energy Physics - Lattice · Physics 2018-04-18 Giuseppe Gagliardi , Jangho Kim , Wolfgang Unger

We improve a previous quenched result for heavy-light pseudoscalar meson decay constants with the light quark taken to be the strange quark. A finer lattice resolution (a ~ 0.05 fm) in the continuum limit extrapolation of the data computed…

High Energy Physics - Lattice · Physics 2008-11-26 Michele Della Morte , Stephan Durr , Damiano Guazzini , Jochen Heitger , Andreas Juttner , Rainer Sommer

The prospects for the measurement of the strong coupling constant alpha_msbar(M_Z) to a relative uncertainty of 1% are discussed. Particular emphasis is placed on the implications relating to future High Energy Physics facilities.

High Energy Physics - Experiment · Physics 2010-11-15 P. N. Burrows , L. Dixon , A. X. El-Khadra , J. W. Gary , W. Giele , D. A. Harris , S. Ritz , B. A. Schumm