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相关论文: A non-perturbative determination of $b_{\rm g}$

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We present a computation of B-meson decay constants from lattice QCD simulations within the framework of Heavy Quark Effective Theory for the b-quark. The next-to-leading order corrections in the HQET expansion are included…

This paper presents a formulation of lattice fermions applicable to all quark masses, large and small. We incorporate interactions from previous light-fermion and heavy-fermion methods, and thus ensure a smooth connection to these limiting…

高能物理 - 格点 · 物理学 2008-11-26 Aida X. El-Khadra , Andreas S. Kronfeld , Paul B. Mackenzie

We compute several matrix elements of dimension-six four-fermion operators and extract their B-parameters. The calculations have been performed with the tree-level Clover action at $\beta = 6.0$. The renormalization constants and mixing…

高能物理 - 格点 · 物理学 2016-09-01 L. Conti , A. Donini , V. Gimenez , G. Martinelli , M. Talevi , A. Vladikas

In this paper we present results for the renormalization of gauge invariant nonlocal fermion operators which contain a Wilson line, to one-loop level in lattice perturbation theory. Our calculations have been performed for Wilson/clover…

高能物理 - 格点 · 物理学 2018-10-03 Martha Constantinou , Haralambos Panagopoulos

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…

高能物理 - 格点 · 物理学 2008-11-26 M. Della Morte , S. Durr , J. Heitger , H. Molke , J. Rolf , A. Shindler , R. Sommer

By combining the first unquenched lattice computation of the B-meson binding energy and the two-loop contribution to the lattice HQET residual mass, we determine the (\bar{{MS}}) (b)-quark mass, (\bar{m}_{b}(\bar{m}_{b})). The inclusion of…

高能物理 - 格点 · 物理学 2011-01-27 V. Gimenez , L. Giusti , G. Martinelli , F. Rapuano

We present a lattice determination of the $\Lambda$ parameter in three-flavor QCD and the strong coupling at the Z pole mass. Computing the nonperturbative running of the coupling in the range from $0.2\,$GeV to $70\,$GeV, and using…

高能物理 - 格点 · 物理学 2017-09-13 M. Bruno , M. Dalla Brida , P. Fritzsch , T. Korzec , A. Ramos , S. Schaefer , H. Simma , S. Sint , R. Sommer

The determinations of $|V_{\rm ub}|$ from the exclusive branching ratios of $B\to \tau \nu$ and $B \to \pi l \nu$ tend to show a tension at the level of $3\sigma$ \cite{Beringer:1900zz}. On the theoretical side they depend on the lattice…

高能物理 - 格点 · 物理学 2012-10-15 Felix Bahr , Fabio Bernardoni , John Bulava , Alberto Ramos , Hubert Simma , Rainer Sommer

We present a precise lattice QCD determination of the b-quark mass, of the B and Bs decay constants and first preliminary results for the B-mesons bag parameter. Simulations are performed with Nf = 2 Wilson twisted mass fermions at four…

We present a lattice QCD computation of the b-quark mass, the B and B_s decay constants, the B-mixing bag parameters for the full four-fermion operator basis as well as determinations for \xi and f_{Bq}\sqrt{B_i^{(q)}} extrapolated to the…

We compute non-perturbatively the renormalisation constants of composite operators on a $16^3 \times 32 $ lattice with lattice spacing $a$ = 0.093 fm for the overlap fermion action by using the regularisation independent (RI) scheme. The…

高能物理 - 格点 · 物理学 2010-03-04 J. B. Zhang , D. B. Leinweber , K. F. Liu , A. G. Williams

We comment on two recent calculations of the second order perturbative corrections in the heavy flavor semileptonic transitions within the Brodsky-Lepage-Mackenzie approach. It is pointed out that the results do not show significant…

高能物理 - 唯象学 · 物理学 2010-11-01 M. Shifman , N. G. Uraltsev

We report on preliminary results of a high statistics quenched lattice QCD calculation of nucleon matrix elements within the Symanzik improvement programme. Using the recently determined renormalisation constants from the Alpha…

高能物理 - 格点 · 物理学 2008-11-26 S. Capitani , M. Goeckeler , R. Horsley , H. Oelrich , H. Perlt , D. Pleiter , P. E. L. Rakow , G. Schierholz , A. Schiller , P. Stephenson

We present a new method aiming at a non-perturbative, model-independent determination of the momentum dependence of the form factors entering semileptonic decays using unitarity and analyticity constraints. We extend the original proposal…

We review the long term project of the ALPHA collaboration to compute in QCD the running coupling constant and quark masses at high energy scales in terms of low energy hadronic quantities. The adapted techniques required to numerically…

高能物理 - 格点 · 物理学 2015-01-09 Rainer Sommer , Ulli Wolff

We present a Lattice QCD determination of the chiral quark condensate based on a new method. We extract the quark condensate from the operator product expansion of the quark propagator at short euclidean distances, where it represents the…

高能物理 - 格点 · 物理学 2011-09-13 V. Gimenez , V. Lubicz , F. Mescia , V. Porretti , J. Reyes

We present the results of the first lattice QCD calculation of the $K \to \pi$ matrix elements of the chromomagnetic operator $O_{CM} = g\, \bar s\, \sigma_{\mu\nu} G_{\mu\nu} d$, which appears in the effective Hamiltonian describing…

高能物理 - 格点 · 物理学 2018-04-11 M. Constantinou , M. Costa , R. Frezzotti , V. Lubicz , G. Martinelli , D. Meloni , H. Panagopoulos , S. Simula

Renormalization factors for local vector and axial vector currents for the Wilson quark action are perturbatively calculated to one loop order including finite quark masses from the ratio of the on-shell quark matrix elements in the Feynman…

高能物理 - 格点 · 物理学 2009-10-30 Yoshinobu Kuramashi

Lattice formulations of QCD with Wilson fermions and a chirally twisted quark mass matrix provide an attractive framework for non-perturbative numerical studies. Owing to reparameterization invariance, the limiting continuum theory is just…

高能物理 - 格点 · 物理学 2009-11-07 R. Frezzotti

We give an introduction to three topics in lattice gauge theory: I. The Schroedinger Functional and O(a) improvement. O(a) improvement has been reviewed several times. Here we focus on explaining the basic ideas in detail and then proceed…

高能物理 - 格点 · 物理学 2007-05-23 Rainer Sommer
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