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Related papers: Four quark operators in maximally twisted Wilson L…

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We outline a general strategy for the non-perturbative renormalisation of composite operators in discretisations based on Neuberger fermions, via a matching to results obtained with Wilson-type fermions. As an application, we consider the…

High Energy Physics - Lattice · Physics 2009-11-11 P. Dimopoulos , L. Giusti , P. Hernandez , F. Palombi , C. Pena , A. Vladikas , J. Wennekers , H. Wittig

Perturbative expansions of several small Wilson loops are computed through next-to-next-to-leading order in unquenched lattice QCD, from Monte Carlo simulations at weak couplings. This approach provides a much simpler alternative to…

High Energy Physics - Lattice · Physics 2009-11-11 Kit Yan Wong , Howard D. Trottier , R. M. Woloshyn

We present an adaptive multigrid solver for application to the non-Hermitian Wilson-Dirac system of QCD. The key components leading to the success of our proposed algorithm are the use of an adaptive projection onto coarse grids that…

High Energy Physics - Lattice · Physics 2010-12-02 R. Babich , J. Brannick , R. C. Brower , M. A. Clark , T. A. Manteuffel , S. F. McCormick , J. C. Osborn , C. Rebbi

We describe how the Schroedinger functional and twisted mass QCD can be used to compute the kaon B-parameter B_K on the lattice with Wilson fermions. This new approach is expected to reduce the systematic uncertainties on B_K through a…

High Energy Physics - Lattice · Physics 2015-06-25 M. Guagnelli , J. Heitger , C. Pena , S. Sint , A. Vladikas

Quantum Chromodynamics on a lattice with Wilson fermions and a chirally twisted mass term for two degenerate quark flavours is considered in the framework of chiral perturbation theory. The pion masses and decay constants are calculated in…

High Energy Physics - Lattice · Physics 2010-12-23 Gernot Münster , Christian Schmidt , Enno E. Scholz

The effective electroweak Hamiltonian in the gradient-flow formalism is constructed for the current-current operators through next-to-next-to-leading order QCD. The results are presented for two common choices of the operator basis. This…

High Energy Physics - Lattice · Physics 2023-03-14 Robert V. Harlander , Fabian Lange

We present selected results obtained by RQCD from simulations of $N_f=2+1$ flavours of non-perturbatively $\mathcal{O}(a)$ improved Wilson fermions, employing open boundary conditions in time. The ensembles were created within the CLS…

By employing a twisted mass term, we compare recent results from lattice calculations of Nf=2 dynamical Wilson fermions with Wilson Chiral Perturbation Theory (WChPT). The final goal is to determine some combinations of Gasser-Leutwyler Low…

High Energy Physics - Lattice · Physics 2010-12-23 L. Scorzato , F. Farchioni , P. Hofmann , K. Jansen , I. Montvay , G. Munster , M. Papinutto , E. E. Scholz , A. Shindler , N. Ukita , C. Urbach , U. Wenger , I. Wetzorke

We present O(g^4) calculations of both planar and non-planar Wilson loops for various actions in the presence of sea quarks. In particular, the plaquette, the static potential and the static self energy are calculated to this order for…

High Energy Physics - Lattice · Physics 2007-05-23 Gunnar S. Bali , Peter Boyle

The perturbative and nonperturbative renormalisation of quark-antiquark operators in lattice QCD with two flavours of clover fermions is investigated within the research programme of the QCDSF collaboration. Operators with up to three…

High Energy Physics - Lattice · Physics 2011-01-27 M. Göckeler , R. Horsley , Y. Nakamura , H. Perlt , D. Pleiter , P. E. L. Rakow , A. Schäfer , G. Schierholz , A. Schiller , H. Stüben , J. M. Zanotti

While the standard model is the most successfully theory to describe all interactions and constituents in elementary particle physics, it has been constantly examined for over four decades. Weak decays of charm quarks can measure the…

High Energy Physics - Lattice · Physics 2022-01-26 Qi-An Zhang , Jun Hua , Fei Huang , Renbo Li , Yuanyuan Li , Cai-Dian Lu , Peng Sun , Wei Sun , Wei Wang , Yi-Bo Yang

Quantum Chromodynamics on a lattice with Wilson fermions and a chirally twisted mass term for two degenerate quark flavours is considered in the framework of chiral perturbation theory. The pion mass and decay constant are calculated in…

High Energy Physics - Lattice · Physics 2010-12-23 Gernot Münster , Christian Schmidt

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 variational method is used widely for determining eigenstates of the QCD hamiltonian for actions with a conventional transfer matrix, e.g., actions with improved Wilson fermions. An alternative lattice fermion formalism, staggered…

High Energy Physics - Lattice · Physics 2015-03-05 Carleton DeTar , Song-Haeng Lee

We summarise status and recent results of the European Twisted Mass collaboration (ETMC). The collaboration has generated gauge configurations for three different values of the lattice spacing smaller or equal 0.1 fm and values of the…

High Energy Physics - Lattice · Physics 2008-11-26 Carsten Urbach

We present results of lattice QCD simulations with mass-degenerate up and down and mass-split strange and charm (N_f = 2+1+1) dynamical quarks using Wilson twisted mass fermions at maximal twist. The tuning of the strange and charm quark…

We present a detailed design of a (P)HMC simulation algorithm for N_f = 2 + 1 + 1 maximally twisted Wilson quark flavours. The algorithm retains even/odd and mass-shift preconditionings combined with multiple Molecular Dynamics time scales…

High Energy Physics - Lattice · Physics 2007-05-23 T. Chiarappa , R. Frezzotti , C. Urbach

We investigate the phase structure of lattice QCD with dynamical Wilson fermions. Wilson chiral perturbation theory predicts that the Aoki phase and the Sharpe-Singleton scenario manifest themselves in very distinct behavior of the Wilson…

High Energy Physics - Lattice · Physics 2013-11-11 Joni M. Suorsa , T. Rantalaiho , K. Rummukainen , K. Splittorff , David J. Weir

The introduction of a chirally twisted mass term has been proposed as an attractive approach to O(a) improvement of Quantum Chromodynamics with Wilson fermions on a lattice. For numerical simulation projects it is important to know the…

High Energy Physics - Lattice · Physics 2010-12-23 Gernot Münster

We give a determination of the phenomenological value of the Wilson (or gradient) flow scales t0 and w0 for 2+1 flavours of dynamical quarks. The simulations are performed keeping the average quark mass constant, which allows the approach…

High Energy Physics - Lattice · Physics 2015-08-25 V. G. Bornyakov , R. Horsley , R. Hudspith , Y. Nakamura , H. Perlt , D. Pleiter , P. E. L. Rakow , G. Schierholz , A. Schiller , H. Stüben , J. M. Zanotti