English
Related papers

Related papers: Three-Loop Results in QCD with Wilson Fermions

200 papers

We present results from an analysis of the light spectrum and the decay constants f_{\pi} and f_V^{-1} in Full QCD with n_f=2 Wilson fermions at a coupling of beta=5.6 on a 16^3x32 lattice.

High Energy Physics - Lattice · Physics 2009-10-28 SESAM-Collaboration , U. Glaessner , S. Guesken , H. Hoeber , Th. Lippert , G. Ritzenhoefer , K. Schilling , G. Siegert , A. Spitz

We describe a way to optimize the chiral behavior of Wilson-type lattice fermion actions by studying the low energy real eigenmodes of the Dirac operator. We find a candidate action, the clover action with fat links with a tuned clover…

High Energy Physics - Lattice · Physics 2009-10-31 Thomas DeGrand , Anna Hasenfratz , Tamas G. Kovacs

The modelling of the ultraviolet contributions to the quark determinant in lattice QCD in terms of a small number of Wilson loops is examined. Complete Dirac spectra are obtained for sizeable ensembles of SU(3) gauge fields at $\beta$=5.7…

High Energy Physics - Lattice · Physics 2016-08-25 A. Duncan , E. Eichten , R. Roskies , H. Thacker

We compute the QCD running coupling on the lattice as defined from the 3-gluon vertex. We present the results of an exploratory study at $\beta=6.0$ on a $16^4$ lattice, which show that for momenta larger than 2 \Gev, the coupling runs…

High Energy Physics - Lattice · Physics 2007-05-23 D. Henty , C. Parrinello , C. Pittori

We compute the ratio between the scale $\Lambda_L$ associated with a lattice formulation of QCD using the overlap-Dirac operator, and $\Lambda_{MS-bar}$. To this end, the one-loop relation between the lattice coupling $g_0$ and the coupling…

High Energy Physics - Lattice · Physics 2015-06-25 C. Alexandrou , E. Follana , H. Panagopoulos , E. Vicari

We present results for the b \bar b spectrum obtained using an O(M_bv^6)-correct non-relativistic lattice QCD action. Propagators are evaluated on SESAM's three sets of dynamical gauge configurations generated with two flavours of Wilson…

High Energy Physics - Lattice · Physics 2009-10-30 A. Spitz , N. Eicker , J. Fingberg , S. Güsken , H. Hoeber , Th. Lippert , K. Schilling , J. Viehoff

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

We have studied the light hadron spectrum and decay constants for quenched QCD at beta=6.2 on a 24^3x48 lattice. We compare the results obtained using a nearest-neighbour O(a)-improved ("clover") fermion action with those obtained using the…

High Energy Physics - Lattice · Physics 2019-06-05 UKQCD Collaboration , presented by Alan D. Simpson

The two loop coefficient of the expansion of the Schroedinger functional coupling in terms of the lattice coupling is calculated for the SU(3) Yang-Mills theory. This coefficient is required to relate lattice data to the MS-bar-coupling. As…

High Energy Physics - Lattice · Physics 2009-10-30 Achim Bode

A comprehensive number of integrals emerging in one-loop computations in a gauge perturbation theory on the lattice with Wilson fermions at $r=1$ is computed using the Burgio--Caracciolo--Pelissetto algorithm and the FORM package. An…

High Energy Physics - Lattice · Physics 2009-02-22 R. N. Rogalyov

We present new results on the static qq-potential from high statistics simulations on 32^4 and smaller lattices, using the standard Wilson beta = 6.0, 6.4, and 6.8. Within our statistical errors we do not observe any finite size effects…

High Energy Physics - Lattice · Physics 2016-08-31 Gunnar S. Bali , Klaus Schilling

We present our result for the $K\to\pi\pi$ decay amplitudes for both the $\Delta I=1/2$ and $3/2$ processes with the improved Wilson fermion action. Expanding on the earlier works by Bernard {\it et al.} and by Donini {\it et al.}, we show…

High Energy Physics - Lattice · Physics 2015-10-14 N. Ishizuka , K. -I. Ishikawa , A. Ukawa , T. Yoshié

We investigate the finite-temperature phase structure and the scaling of the chiral condensate in lattice QCD with two degenerate light quarks, using a renormalization group improved gauge action and the Wilson quark action. We obtain a…

High Energy Physics - Lattice · Physics 2009-10-30 S. Aoki , Y. Iwasaki , K. Kanaya , S. Kaya , A. Ukawa , T. Yoshié

We present a lattice QCD determination of the b quark mass and of the B and B_s decay constants, performed with N_f=2 twisted mass Wilson fermions, by simulating at four values of the lattice spacing. In order to study the b quark on the…

We extend the epsilon-expansion of continuum chiral perturbation theory to nonzero lattice spacing in the framework of Wilson Chiral Perturbation Theory. We distinguish various regimes by defining the relative power counting of the quark…

High Energy Physics - Lattice · Physics 2010-11-05 Oliver Bar , Silvia Necco , Stefan Schaefer

We describe the calculation of the three-loop QCD corrections to quark and gluon form factors. The relevant three-loop Feynman diagrams are evaluated and the resulting three-loop Feynman integrals are reduced to a small set of known master…

High Energy Physics - Phenomenology · Physics 2023-11-15 T. Gehrmann , E. W. N. Glover , T. Huber , N. Ikizlerli , C. Studerus

Quark currents renormalization constants can in principle be safely computed in lattice perturbation theory. In practice, traditional lattice perturbative computations are quite cumbersome, so that so far only the first loop results were…

High Energy Physics - Lattice · Physics 2007-05-23 F. Di Renzo , A. Mantovi , V. Miccio , C. Torrero , L. Scorzato

Using the Schr\"odinger functional (SF) with a single staggered fermion field we calculate the SF coupling in four-flavour QCD for a wide range of energies and lattice sizes up to $L/a=16$. Preliminary results for the continuum…

High Energy Physics - Lattice · Physics 2010-12-01 Paula Pérez-Rubio , Stefan Sint

In this joint contribution we announce the formation of the "OPEN LATtice initiative", https://openlat1.gitlab.io, to study Stabilised Wilson Fermions (SWF). They are a new avenue for QCD calculations with Wilson-type fermions and we report…

We present an update on Numerical Stochastic Perturbation Theory projects for Lattice QCD, which are by now run on apeNEXT. As a first issue, we discuss a strategy to tackle finite size effects which can be quite sizeable in the computation…

High Energy Physics - Lattice · Physics 2009-04-14 Francesco Di Renzo , Luigi Scorzato , Christian Torrero