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Related papers: Alpha_s from the Lattice Potential

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We use lattice QCD simulations, with MILC gluon configurations and HISQ c-quark propagators, to make very precise determinations of moments of charm-quark pseudoscalar, vector and axial-vector correlators. These moments are combined with…

The QCD analytic running coupling alpha_{an} which has no nonphysical singularities for all Q^2>0 is considered for the initial perturbation theory approximations up to four loop order. The finiteness of the analytic coupling at zero is…

High Energy Physics - Phenomenology · Physics 2009-11-07 Aleksey I. Alekseev

We present an overview of the recent lattice determination of the QCD coupling $\alpha_s$ by the ALPHA Collaboration. The computation is based on the non-perturbative determination of the $\Lambda$-parameter of $N_{\rm f}=3$ QCD, and the…

High Energy Physics - Phenomenology · Physics 2018-12-18 Mattia Dalla Brida

We revisit the static potential for the $Q Q \bar Q \bar Q$ system using SU(3) lattice simulations, studying both the colour singlets groundstate and first excited state. We consider geometries where the two static quarks and the two…

High Energy Physics - Lattice · Physics 2017-11-01 P. Bicudo , M. Cardoso , O. Oliveira , P. J. Silva

We obtain a determination of the strong coupling alpha_s in quantum chromodynamics, by comparing perturbative calculations for the short-distance part of the static energy with lattice computations. Our result reads…

High Energy Physics - Phenomenology · Physics 2012-11-21 Xavier Garcia i Tormo

Existing lattice data on the QCD phase transition are analyzed in renormalized perturbation theory. In quenched QCD it is found that T_c scales for lattices with only 3 time slices, and that T_c/Lambda_msbar=1.15 \pm 0.05. A preliminary…

High Energy Physics - Lattice · Physics 2009-10-31 Sourendu Gupta

We present a determination of the QCD coupling constant, $\alpha_s$, obtained by fitting lattice results for the flavour $ud$ hadronic vacuum polarisation function to continuum perturbation theory. We use $n_f=2+1$ flavours of Domain Wall…

High Energy Physics - Lattice · Physics 2018-07-09 Renwick J. Hudspith , Randy Lewis , Kim Maltman , Eigo Shintani

We report on the latest results on the running coupling of two flavour QCD in the Schr\"odinger functional scheme. Results for the step scaling function are obtained from simulations on lattices $L/a=8$ and $L/a=16$ which confirm the first…

High Energy Physics - Lattice · Physics 2009-11-07 M. Della Morte , R. Frezzotti , J. Heitger , F. Knechtli , J. Rolf , R. Sommer , U. Wolff

We present our latest study of Lambda-Nucleon (LN) interaction by using lattice QCD, following up on our report at LATTICE 2008. We have calculated not only the scattering lengths but also the central and tensor potentials, which are…

High Energy Physics - Lattice · Physics 2010-11-05 H. Nemura , for HAL QCD , PACS-CS Collaboration

We study the $\Lambda$-nucleon ($\Lambda N$) force by using lattice QCD. The Bethe-Salpeter amplitude is calculated for the lowest scattering state of the $\Lambda N$ so as to obtain the $\Lambda N$ potential. The numerical calculation is…

High Energy Physics - Lattice · Physics 2010-01-21 H. Nemura , N. Ishii , S. Aoki , T. Hatsuda , for PACS-CS Collaboration

We determine the strong coupling constant $\alpha_s$ from a lattice calculation of vacuum polarization functions (VPF) in three-flavor QCD with dynamical overlap fermions. Fitting lattice data of VPF to the continuum perturbative formula…

High Energy Physics - Lattice · Physics 2014-09-05 E. Shintani , S. Aoki , H. Fukaya , S. Hashimoto , T. Kaneko , T. Onogi , N. Yamada

We perform the first study for the static penta-quark (5Q) potential in lattice QCD with $\beta$=6.0 and $16^3 \times 32$ at the quenched level. Accurate results of the 5Q potential are extracted from the 5Q Wilson loop using the smearing…

High Energy Physics - Lattice · Physics 2017-08-23 Fumiko Okiharu , Hideo Suganuma , Toru T. Takahashi

We report on an estimate of \alpha_s, renormalised in the MSbar scheme at the tau and Z^0 mass scales, by means of lattice QCD. Our major improvement compared to previous lattice calculations is that, for the first time, no perturbative…

High Energy Physics - Lattice · Physics 2015-06-11 B. Blossier , Ph. Boucaud , M. Brinet , F. De Soto , X. Du , V. Morenas , O. Pene , K. Petrov , J. Rodriguez-Quintero

We report on very strong evidence of the occurrence of power terms in $\as(p)$, the QCD running coupling constant in the $\widetilde{MOM}$ scheme, by analyzing non-perturbative measurements from the lattice three-gluon vertex between 2.0…

High Energy Physics - Phenomenology · Physics 2010-03-19 Ph. Boucaud , G. Burgio , F. Di Renzo , J. P. Leroy , J. Micheli , C. Parrinello , O. Pène , C. Pittori , J. Rodríguez-Quintero , C. Roiesnel , K. Sharkey

We study deviations from the perturbative asymptotic behaviour in the running QCD coupling by analysing non-perturbative measurements of alpha_s (p) at low momenta as obtained from the lattice three-gluon vertex. Our exploratory study…

High Energy Physics - Phenomenology · Physics 2009-10-31 G. Burgio , F. Di Renzo , C. Parrinello , C. Pittori

We determine the three-loop coefficient of the beta function in the asymmetric momentum subtraction scheme in Landau gauge. This scheme is convenient for lattice studies of \alpha_s, the running coupling constant of QCD. We present high…

High Energy Physics - Phenomenology · Physics 2010-03-19 Ph. Boucaud , J. P. Leroy , J. Micheli , O. Pene , C. Roiesnel

We calculate, to 3 loops in perturbation theory, the bare $\beta$-function of QCD, formulated on the lattice with the clover fermionic action. The dependence of our result on the number of colors $N$, the number of fermionic flavors $N_f$,…

High Energy Physics - Lattice · Physics 2009-11-07 A. Bode , H. Panagopoulos

We present an update on our previous determination of the Lambda parameter in QCD. The main emphasis is on results for two flavours of light dynamical quarks, where we can now almost double the amount of data used, including values at…

High Energy Physics - Lattice · Physics 2008-11-26 M. Göckeler , R. Horsley , A. C. Irving , D. Pleiter , P. E. L. Rakow , G. Schierholz , H. Stüben

Low-lying $\Lambda$ baryons with spin 1/2 are analyzed in two-flavor unquenched lattice QCD. We construct $2 \times 2$ cross correlators from flavor SU(3) ``octet'' and ``singlet'' baryon operators, and diagonalize them so that we can…

High Energy Physics - Lattice · Physics 2010-11-05 Toru T. Takahashi , Makoto Oka

We study the asymptotic short-distance behaviour as well as the asymptotic large-distance behaviour of the gauge-invariant quark-antiquark nonlocal condensates in QCD. A comparison of some analytical results with the available lattice data…

High Energy Physics - Lattice · Physics 2015-06-25 Enrico Meggiolaro