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Related papers: Exploring two non-perturbative definitions of $c_A…

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It is shown how on-shell O(a) improvement can be implemented non-perturbatively in lattice QCD with Wilson quarks. Improvement conditions are obtained by requiring the PCAC relation to hold exactly in certain matrix elements. These are…

High Energy Physics - Lattice · Physics 2009-10-28 M. Lüscher , S. Sint , R. Sommer , P. Weisz , H. Wittig , U. Wolff

We determine the improvement coefficients b_m and b_a-bp in quenched lattice QCD for a range of beta-values, which is relevant for current large scale simulations. At fixed beta, the results are rather sensitive to the precise choices of…

High Energy Physics - Lattice · Physics 2008-11-26 Marco Guagnelli , Roberto Petronzio , Juri Rolf , Stefan Sint , Rainer Sommer , Ulli Wolff

We report on an ongoing non-perturbative determination of the improvement coefficient of the axial current, $c_\mathrm A$, with three flavours of dynamical $\mathrm O(a)$ improved Wilson quarks and tree-level Symanzik improved gauge action.…

High Energy Physics - Lattice · Physics 2013-12-13 John Bulava , Michele Della Morte , Jochen Heitger , Christian Wittemeier

The coefficients multiplying the counterterms required for O($a$) improvement of the action and the isovector axial current in lattice QCD are computed non-perturbatively, in the quenched approximation and for bare gauge couplings $g_0$ in…

High Energy Physics - Lattice · Physics 2016-09-01 Martin Luescher , Stefan Sint , Rainer Sommer , Peter Weisz , Ulli Wolff

A non-perturbative determination of the axial current improvement coefficient cA is performed with two flavors of dynamical improved Wilson fermions and plaquette gauge action. The improvement condition is formulated with Schroedinger…

High Energy Physics - Lattice · Physics 2008-11-26 Michele Della Morte , Roland Hoffmann , Rainer Sommer

We non-perturbatively calculate the renormalization factor of the static axial vector current in O(a) improved quenched lattice QCD. Its scale dependence is mapped out in the Schroedinger functional scheme by means of a recursive…

High Energy Physics - Lattice · Physics 2009-11-07 Jochen Heitger , Martin Kurth , Rainer Sommer

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

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

By considering the local vector current between nucleon states and imposing charge conservation we determine, for $O(a)$ improved Wilson fermions, its renormalisation constant and quark mass improvement coefficient. The computation is…

High Energy Physics - Lattice · Physics 2008-11-26 T. Bakeyev , M. Gockeler , R. Horsley , D. Pleiter , P. E. L. Rakow , A. Schafer , G. Schierholz , H. Stuben

We develop a strategy for the non-perturbative determination of the O(a)-improvement coefficient c_sw for Wilson fermions with massive sea quarks. The improvement condition is defined via the PCAC relation in the Schr\"odinger functional.…

High Energy Physics - Lattice · Physics 2015-01-28 Patrick Fritzsch , Rainer Sommer , Felix Stollenwerk , Ulli Wolff

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 in the bulk. The elimination of bulk O(a) terms requires the…

High Energy Physics - Lattice · Physics 2010-01-26 Jenifer Gonzalez Lopez , Karl Jansen , Dru B. Renner , Andrea Shindler

We present a new normalization condition for the axial current, which is derived from the PCAC relation with non-vanishing mass. Using this condition reduces the O(r_0 m) corrections to the axial current normalization constant Z_A for an…

High Energy Physics - Lattice · Physics 2009-11-10 R. Hoffmann , F. Knechtli , J. Rolf , R. Sommer , U. Wolff

We present our preliminary results of the non-perturbative determination of the valence mass dependent coefficients $b_\mathrm{A}-b_\mathrm{P}$ and $b_\mathrm{m}$ as well as the ratio $Z_\mathrm{P} Z_\mathrm{m}/ Z_\mathrm{A}$ entering the…

High Energy Physics - Lattice · Physics 2017-10-20 Giulia Maria de Divitiis , Maurizio Firrotta , Jochen Heitger , Carl Christian Köster , Anastassios Vladikas

We investigate Wilson twisted mass fermions in the quenched approximation using different definitions of the critical bare quark mass m_c to realize maximal twist and, correspondingly, automatic O(a) improvement for physical observables. A…

High Energy Physics - Lattice · Physics 2020-06-17 K. Jansen , M. Papinutto , A. Shindler , C. Urbach , I. Wetzorke

We present a scaling investigation of some correlation functions in $\Or(a)$ improved quenched lattice QCD. In particular, as one observable the renormalized PCAC quark mass is considered. Others are constructed such that they become the…

High Energy Physics - Lattice · Physics 2015-06-25 Jochen Heitger

We present a new normalization condition for the axial current, derived from the PCAC relation with non-vanishing quark mass. This condition is expected to reduce mass effects in the chiral extrapolation of the results for the normalization…

High Energy Physics - Lattice · Physics 2009-11-11 Michele Della Morte , Roland Hoffmann , Francesco Knechtli , Rainer Sommer , Ulli Wolff

We investigate the scaling behaviour of quenched Wilson twisted mass fermions at maximal twist applying two definitions of the critical mass. The first definition uses the vanishing of the pseudoscalar meson mass m_PS while the second…

High Energy Physics - Lattice · Physics 2009-11-11 K. Jansen , M. Papinutto , A. Shindler , C. Urbach , I. Wetzorke

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 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 describe a non-perturbative determination of $c_A$ using correlators containing the axial-vector and pseudoscalar currents at zero and non-zero momentum. We apply the method of Bhattacharya et al to extract $c_A$ from the requirement…

High Energy Physics - Lattice · Physics 2009-10-31 S. Collins , C. T. H. Davies
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