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Related papers: Determining gA using non-perturbatively O(a) impro…

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We compute non-perturbatively the renormalization constants of quark bilinears on the lattice in the quenched approximation at three values of the coupling beta=6/g_0^2=6.0,6.2,6.4 using both the Wilson and the tree-level improved SW-Clover…

High Energy Physics - Lattice · Physics 2009-10-31 V. Gimenez , L. Giusti , F. Rapuano , M. Talevi

We present an exploratory study of a gauge-invariant non-perturbative renormalization technique. The renormalization conditions are imposed on correlation functions of composite operators in coordinate space on the lattice. Numerical…

High Energy Physics - Lattice · Physics 2009-11-10 V. Gimenez , L. Giusti , S. Guerriero , V. Lubicz , G. Martinelli , S. Petrarca , J. Reyes , B. Taglienti , E. Trevigne

In calculating hadronic contributions to precision observables for tests of the Standard Model in lattice QCD, the electromagnetic current plays a central role. Using a Wilson action with O($a$) improvement in QCD with $N_{\mathrm{f}}$…

High Energy Physics - Lattice · Physics 2019-02-20 Antoine Gerardin , Tim Harris , Harvey B. Meyer

Using unimproved and non-perturbatively O(a) improved Wilson fermions, results are given for the three lowest moments of unpolarised nucleon structure functions. Renormalisation, chiral extrapolation and the continuum limit of the matrix…

High Energy Physics - Lattice · Physics 2008-11-26 S. Capitani , M. Gockeler , R. Horsley , D. Pleiter , P. Rakow , H. Stuben , G. Schierholz

The ALPHA collaboration has determined the O(a) improved Wilson quark action for lattice spacings $a\leq 0.1$ fm, in the quenched approximation. We extend this result to coarser lattices, $a\leq 0.17$ fm, and calculate the hadron spectrum…

High Energy Physics - Lattice · Physics 2009-10-30 R. G. Edwards , U. M. Heller , T. R. Klassen

We investigate implications of the use of the point-split axial vector current derived from a Wilson like fermionic action. We compute the corresponding renormalization factor nonperturbatively for one beta value. The axial charge gA…

High Energy Physics - Lattice · Physics 2016-12-16 R. Horsley , S. Kazmin , Y. Nakamura , H. Perlt , P. E. L. Rakow , G. Schierholz , A. Schiller , J. M. Zanotti

The use of chirally rotated boundary conditions provides a formulation of the Schroedinger functional that is compatible with automatic O(a) improvement of Wilson fermions up to O(a) boundary contributions. The elimination of bulk O(a)…

High Energy Physics - Lattice · Physics 2015-06-11 J. Gonzalez Lopez , K. Jansen , D. B. Renner , A. Shindler

Renormalization constants can be computed by means of Numerical Stochastic Perturbation Theory to two/three loops in lattice perturbation theory, both in the quenched approximation and in the full (unquenched) theory. As a case of study we…

High Energy Physics - Lattice · Physics 2009-11-10 F. Di Renzo , A. Mantovi , V. Miccio , L. Scorzato , C. Torrero

We perform a non-perturbative determination of the improvement coefficient c_A to remove O(a) discretization errors in the axial vector current in three-flavor lattice QCD with the Iwasaki gauge action and the standard O$(a)$-improved…

High Energy Physics - Lattice · Physics 2010-10-27 T. Kaneko , S. Aoki , M. Della Morte , S. Hashimoto , R. Hoffmann , R. Sommer

We present the first numerical implementation of a non-perturbative renormalization method for lattice operators, based on the study of correlation functions in coordinate space at short Euclidean distance. The method is applied to compute…

High Energy Physics - Lattice · Physics 2009-11-10 V. Gimenez , L. Giusti , S. Guerriero , V. Lubicz , G. Martinelli , S. Petrarca , J. Reyes , B. Taglienti , E. Trevigne

We present a status report on our calculation of the renormalization constants for the quark bilinears in quenched (O(a)) improved Wilson theory at (beta=6.4) using quark states in Landau gauge.

High Energy Physics - Lattice · Physics 2010-05-27 Tanmoy Bhattacharya , Rajan Gupta , Weonjong Lee

Using Schroedinger functional techniques, we determine the coefficient of the clover term necessary for non-perturbative O(a) improvement of hypercubic smeared Wilson fermions on a quenched plaquette action background. Unlike for unsmeared…

High Energy Physics - Lattice · Physics 2008-11-26 Roland Hoffmann , Anna Hasenfratz , Stefan Schaefer

Non-perturbative results for improvement and renormalization constants needed for on-shell and off-shell O(a) improvement of bilinear operators composed of Wilson fermions are presented. The calculations have been done in the quenched…

High Energy Physics - Lattice · Physics 2009-09-29 Tanmoy Bhattacharya , Rajan Gupta , Weonjong Lee , Stephen R. Sharpe

We present the results of a non-perturbative determination of the improvement coefficient $c_\mathrm{V}$ and the renormalisation factor $Z_\mathrm{V}$, which define the renormalised vector current in three-flavour $\mathrm{O}(a)$ improved…

High Energy Physics - Lattice · Physics 2021-04-07 Jochen Heitger , Fabian Joswig

We calculate non-perturbatively the coefficient c_sw required for O(a) improvement of the SU(3) gauge theory with Nf = 2 fermions in the two-index symmetric (sextet) representation. For the calculations we impose the standard improvement…

High Energy Physics - Lattice · Physics 2017-01-13 Martin Hansen

We present a method to compute non-perturbatively the renormalization constant of the scalar density for Ginsparg-Wilson fermions. It relies on chiral symmetry and is based on a matching of renormalization group invariant masses at fixed…

High Energy Physics - Lattice · Physics 2010-02-03 Pilar Hernandez , Karl Jansen , Laurent Lellouch , Hartmut Wittig

We report on the determination of the improvement coefficient $c_{\rm A}$ for the non-singlet axial-vector current $A^{a}_{\mu}(x)$ in the framework of stabilised Wilson-Clover fermions within three flavour lattice QCD. This is done by…

High Energy Physics - Lattice · Physics 2022-12-22 Patrick Fritzsch , Jochen Heitger , Justus T. Kuhlmann

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

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

We present results for the mass spectrum and decay constants using non-perturbatively O(a) improved Wilson fermions. Three values of $\beta$ and 30 different quark masses are used to obtain the chiral and continuum limits. Special emphasis…

High Energy Physics - Lattice · Physics 2015-06-25 M. Goeckeler , R. Horsley , D. Petters , D. Pleiter , P. E. L. Rakow , G. Schierholz , P. Stephenson