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Related papers: Non-perturbative determination of improvement coef…

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Recently the asymptotic lattice spacing dependence of spectral quantities in lattice QCD has been computed to $\mathrm{O}(a^2)$ using Symanzik Effective theory [1,2]. Here, we extend these results to matrix elements and correlators of local…

High Energy Physics - Lattice · Physics 2024-09-04 Nikolai Husung

The use of Heavy Quark Effective Theory (HQET) on the lattice as an approach to B-physics phenomenology is based on a non-perturbative matching of HQET to QCD in finite volume. As a first step to apply the underlying strategy in the…

High Energy Physics - Lattice · Physics 2018-11-08 Patrick Fritzsch , Jochen Heitger , Simon Kuberski

We describe the extension of the improvement program for bilinear operators composed of Wilson fermions to non-degenerate dynamical quarks. We consider two, three and four flavors, and both flavor non-singlet and singlet operators. We find…

High Energy Physics - Lattice · Physics 2009-11-11 Tanmoy Bhattacharya , Rajan Gupta , Weonjong Lee , Stephen R. Sharpe , Jackson M. S. Wu

For the first time, we compute non-perturbatively, i.e. without lattice perturbation theory, the renormalization constants of two-fermion operators in the quenched approximation at $\beta=6.0$, 6.2 and 6.4 using the Wilson and the…

High Energy Physics - Phenomenology · Physics 2009-10-31 V. Gimenez

We improve the non-relativistic QCD (NRQCD) action by comparing the dispersion relation to that of the continuum through $\mathcal{O}(p^6)$ in perturbation theory. The one-loop matching coefficients of the $\mathcal{O}(p^4)$ kinetic…

High Energy Physics - Lattice · Physics 2019-03-27 Christine T. H. Davies , Judd Harrison , Ciaran Hughes , Ronald R. Horgan , Georg M. von Hippel , Matthew Wingate

We present our progress on the computation of the axial form factor of the nucleon with flavour structure $u+d-2s$ from lattice QCD. We employ a set of $N_f=2+1$ CLS ensembles with $O(a)$-improved Wilson fermions and the L\"uscher-Weisz…

We derive chiral Ward identities for lattice QCD with Wilson quarks and $N_\mathrm{f} \geq 3$ flavours, on small lattices with Schr\"odinger functional boundary conditions and vanishingly small quark masses. These identities relate the…

High Energy Physics - Lattice · Physics 2021-08-10 Jochen Heitger , Fabian Joswig , Anastassios Vladikas

We present a lattice-QCD calculation of the hadronic form factors for $B$-meson semileptonic decays computed using the highly improved staggered quark action for both valence and sea quarks on the MILC collaborations 2+1+1-flavor ensembles…

We present a study of leptonic $B$ meson decay constants in lattice QCD with two flavors ($N_f=2$) of light dynamical quarks using NRQCD for the heavy quark. Gauge configurations are generated with a renormalization-group improved gauge…

We carry out a perturbative determination of mass dependent renormalization factors and $O(a)$ improvement coefficients for the vector and axial vector currents with a relativistic heavy quark action, which we have designed to control…

High Energy Physics - Lattice · Physics 2010-04-05 Sinya Aoki , Yasuhisa Kayaba , Yoshinobu Kuramashi

We extend an earlier study of the Landau gauge quark propagator in quenched QCD where we used two forms of the O(a)-improved propagator with the Sheikholeslami-Wohlert quark action. In the present study we use the nonperturbative value for…

High Energy Physics - Lattice · Physics 2010-03-04 Jonivar Skullerud , Derek B. Leinweber , Anthony G. Williams

We determine the masses, the singlet and octet decay constants as well as the anomalous matrix elements of the $\eta$ and $\eta^\prime$ mesons in $N_f=2+1$ QCD\@. The results are obtained using twenty-one CLS ensembles of non-perturbatively…

High Energy Physics - Lattice · Physics 2021-08-27 Gunnar S. Bali , Vladimir Braun , Sara Collins , Andreas Schäfer , Jakob Simeth

We present preliminary results for the charm quark mass in the $N_f=4$ RGI scheme. These were obtained using $N_f=2+1$ CLS ensembles with $\mathcal{O}(a)$ non-perturbatively improved Wilson fermions. We employed five different lattice…

High Energy Physics - Lattice · Physics 2022-06-10 Gunnar Bali , Sjoerd Bouma , Sara Collins , Wolfgang Söldner

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…

High Energy Physics - Lattice · Physics 2008-11-26 Aida X. El-Khadra , Andreas S. Kronfeld , Paul B. Mackenzie

We apply chiral perturbation theory to the pseudoscalar meson mass and decay constant data obtained in the PACS-CS Project toward 2+1 flavor lattice QCD simulations with the O(a)-improved Wilson quarks. We examine the existence of chiral…

We present the results for a perturbative determination of mass dependent improvement coefficients $\nu$, $r_s$, $c_E$ and $c_B$ in a relativistic heavy quark action, which we have designed to control $m_Qa$ errors by extending the on-shell…

High Energy Physics - Lattice · Physics 2009-11-10 Sinya Aoki , Yasuhisa Kayaba , Yoshinobu Kuramashi

We present the first unquenched lattice-QCD calculation of the hadronic form factors for the exclusive decay $\overline{B} \rightarrow D \ell \overline{\nu}$ at nonzero recoil. We carry out numerical simulations on fourteen ensembles of…

We report on an investigation of the LANL method for determining the O(a) improvement coefficient c_A nonperturbatively. We find we are able to extract reliable estimates for the coefficient using this method. However, our study of…

High Energy Physics - Lattice · Physics 2008-11-26 S. Collins , C. T. H. Davies , G. P. Lepage , J. Shigemitsu

SU(2) gauge theory with two fermions transforming under the adjoint representation may appear conformal or almost conformal in the infrared, and is one of the candidate theories for building models for technicolor. Early lattice Monte Carlo…

High Energy Physics - Lattice · Physics 2015-05-20 Tuomas Karavirta , Anne Mykkanen , Jarno Rantaharju , Kari Rummukainen , Kimmo Tuominen

The determination of quark masses from lattice QCD simulations requires a non-perturbative renormalization procedure and subsequent scale evolution to high energies, where a conversion to the commonly used MS-bar scheme can be safely…

High Energy Physics - Lattice · Physics 2018-06-07 Isabel Campos , Patrick Fritzsch , Carlos Pena , David Preti , Alberto Ramos , Anastassios Vladikas