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Related papers: Non-perturbative determination of improvement coef…

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We report on a non-perturbative computation of the renormalization factor Z_A of the axial vector current in three-flavour O(a) improved lattice QCD with Wilson quarks and tree-level Symanzik improved gauge action and also recall our recent…

High Energy Physics - Lattice · Physics 2015-03-02 John Bulava , Michele Della Morte , Jochen Heitger , Christian Wittemeier

We consider O(a) improvement for two flavor lattice QCD. The improvement term in the action is computed non-perturbatively for a large range of the bare coupling. The position of the critical line and higher order lattice artifacts…

High Energy Physics - Lattice · Physics 2009-10-31 Karl Jansen , Rainer Sommer

With Wilson quarks, on-shell O($a$) improvement of the lattice QCD action is achieved by including the Sheikholeslami-Wohlert term and two further operators of mass dimension 5, which amount to a mass-dependent rescaling of the bare…

High Energy Physics - Lattice · Physics 2024-02-02 Mattia Dalla Brida , Roman Höllwieser , Francesco Knechtli , Tomasz Korzec , Stefan Sint , Rainer Sommer

By imposing axial and vector Ward identities for flavour-non-singlet currents, we estimate in the quenched approximation the non-perturbative values of combinations of improvement coefficients, which appear in the expansion around the…

High Energy Physics - Lattice · Physics 2009-10-30 G. M. de Divitiis , R. Petronzio

The coefficient c_A required for O(a) improvement of the axial current in lattice QCD with N_f=3 flavors of Wilson fermions and the tree-level Symanzik-improved gauge action is determined non-perturbatively. The standard improvement…

High Energy Physics - Lattice · Physics 2015-12-09 John Bulava , Michele Della Morte , Jochen Heitger , Christian Wittemeier

We present a two-flavor QCD calculation of $B_K$ on a $16^3 \times 32$ lattice at $a\sim 0.12$ fm (or equivalently $a^{-1}\sim$1.67 GeV). Both valence and sea quarks are described by the overlap fermion formulation. The matching factor is…

High Energy Physics - Lattice · Physics 2019-08-13 S. Aoki , H. Fukaya , S. Hashimoto , J. Noaki , T. Kaneko , H. Matsufuru , T. Onogi , N. Yamada

We perform the non-perturbative renormalization of matrix elements of the static-light axial current by a computation of its scale dependence in lattice QCD with two flavours of massless O(a) improved Wilson quarks. The regularization…

High Energy Physics - Lattice · Physics 2010-10-27 Michele Della Morte , Patrick Fritzsch , Jochen Heitger

We perform hybrid Monte Carlo simulation of (2+1+1)-flavors lattice QCD with the optimal domain-wall fermion (which has the effective 4D Dirac operator exactly equal to the Zolotarev optimal rational approximation of the overlap Dirac…

High Energy Physics - Lattice · Physics 2017-02-09 Yu-Chih Chen , Ting-Wai Chiu

We non-perturbatively determine the renormalization constant and the improvement coefficients relating the renormalized current and subtracted quark mass in O(a) improved two-flavour lattice QCD. We employ the Schr\"odinger functional…

High Energy Physics - Lattice · Physics 2010-10-06 Patrick Fritzsch , Jochen Heitger , Nazario Tantalo

We compute the hadron mass spectrum, the quark masses and the meson decay constants in quenched lattice QCD with non-perturbatively $O(a)$ improved Wilson fermions. The calculations are done for two values of the coupling constant, $\beta =…

High Energy Physics - Lattice · Physics 2008-11-26 M. Göckeler , R. Horsley , H. Perlt , P. Rakow , G. Schierholz , A. Schiller , P. Stephenson

We perform a non-perturbative determination of the O(a)-improvement coefficient c_SW for the Wilson quark action in three-flavor QCD with the plaquette gauge action. Numerical simulations are carried out in a range of \beta=12.0-5.2 on a…

We have simulated QCD using 2+1 flavors of domain wall quarks on a $(2.74 {\rm fm})^3$ volume with an inverse lattice scale of $a^{-1} = 1.729(28)$ GeV. The up and down (light) quarks are degenerate in our calculations and we have used four…

We report on our Ward identity determination of the $\mathrm{O}(a)$ improvement coefficient for the flavour singlet scalar density, namely $g_\mathrm{S}$, from three-flavour lattice QCD with Wilson-clover fermions and the tree-level…

High Energy Physics - Lattice · Physics 2025-02-14 Pia Leonie Jones Petrak , Jochen Heitger , Fabian Joswig

The explicit breaking of chiral symmetry of the Wilson fermion action results in additive quark mass renormalization. Moreover, flavour singlet and non-singlet scalar currents acquire different renormalization constants with respect to…

High Energy Physics - Lattice · Physics 2016-10-12 Gunnar S. Bali , Enno E. Scholz , Jakob Simeth , Wolfgang Söldner

We demonstrate a method for calculating the neutral B-meson decay constants and mixing matrix elements in unquenched lattice QCD with domain-wall light quarks and static b-quarks. Our computation is performed on the "2+1" flavor gauge…

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

We determine the parameter c_SW required for O(a)-improvement of the three flavor Wilson fermion action together with the tree-level Symanzik improved gauge action. The standard improvement condition is employed for a range of couplings.…

High Energy Physics - Lattice · Physics 2015-06-15 John Bulava , Stefan Schaefer

We non-perturbatively determine the renormalization factor of the axial vector current in lattice QCD with $N_f=3$ flavors of Wilson-clover fermions and the tree-level Symanzik-improved gauge action. The (by now standard) renormalization…

High Energy Physics - Lattice · Physics 2016-06-29 John Bulava , Michele Della Morte , Jochen Heitger , Christian Wittemeier

Precise theoretical predictions derived from the Standard Model are a key ingredient in searches for new physics in the flavor sector. The large mass and long lifetime of the $b$ quark make processes involving $b$ quarks of particular…

High Energy Physics - Phenomenology · Physics 2020-12-09 Jonathan M. Flynn , Ryan C. Hill , Andreas Jüttner , Amarjit Soni , J. Tobias Tsang , Oliver Witzel

Many observables of interest in lattice QCD are extracted from correlation functions involving the vector current. If Wilson fermions are used, it is therefore of practical importance that, besides the action, the current be O($a$) improved…

High Energy Physics - Lattice · Physics 2015-12-16 Tim Harris , Harvey B. Meyer