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

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Hamiltonian lattice QCD with Wilson fermions is investigated systematically by strong-coupling expansion up to the second order. The effective Hamiltonian is diagonalized by Bogoliubov transformation. The vacuum energy, chiral condensate,…

High Energy Physics - Lattice · Physics 2009-11-07 Yi-Zhong Fang , Xiang-Qian Luo

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

We match continuum and lattice heavy-light four-fermion operators at one loop in perturbation theory. For the heavy quarks we use nonrelativistic QCD and for the massless light quarks the highly improved staggered quark action. We include…

High Energy Physics - Lattice · Physics 2014-10-02 Christopher Monahan , Elvira Gamiz , Ron Horgan , Junko Shigemitsu

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

We compute $\Lambda_{\bar{MS}}$ for two flavors of light dynamical quarks using non-perturbatively $O(a)$ improved Wilson fermions. We improve on a recent calculation by employing Pad\'e-improved two-loop and three-loop perturbation theory…

High Energy Physics - Lattice · Physics 2008-11-26 S. Booth , M. Göckeler , R. Horsley , A. C. Irving , B. Joo , S. Pickles , D. Pleiter , P. E. L. Rakow , G. Schierholz , Z. Sroczynski , H. Stüben

We presents results for the matrix elements of a variety of four-fermion operators calculated using quenched Wilson fermions. Our simulations are done on 170 lattices of size $32^3 x 64$ at $\beta = 6.0$. We find $B_K=0.74 +- 0.04 +- 0.05$,…

High Energy Physics - Lattice · Physics 2008-02-03 Rajan Gupta , Tanmoy Bhattacharya , Stephen Sharpe

We study QCD with two flavors of dynamical Wilson fermions at $\beta = 5.5$ and three values of $\kappa$. The corresponding pion masses are 0.375, 0.324 and 0.262 in lattice units, with pion to rho mass ratios of 0.76, 0.71 and 0.62,…

High Energy Physics - Lattice · Physics 2009-10-28 K. M. Bitar , R. G. Edwards , U. M. Heller , A. D. Kennedy

We show at the example of the matrix element between pion states of a twist-2, non-singlet operator that Wilson twisted mass fermions allow to compute this phenomenologically relevant quantitiy at small pseudo scalar masses of O(270 MeV).…

High Energy Physics - Lattice · Physics 2007-05-23 S. Capitani , K. Jansen , M. Papinutto , A. Shindler , I. Wetzorke , C. Urbach

Within the framework of quenched lattice QCD and using O(a) improved Wilson fermions and non-perturbative renormalisation, a high statistics computation of low moments of the unpolarised nucleon structure functions is given. Particular…

High Energy Physics - Phenomenology · Physics 2008-11-26 M. Göckeler , R. Horsley , D. Pleiter , P. E. L. Rakow , G. Schierholz

Quantum Chromodynamics on a lattice with Wilson fermions and a chirally twisted mass term is considered in the framework of chiral perturbation theory. For two and three numbers of quark flavours, respectively, with non-degenerate quark…

High Energy Physics - Lattice · Physics 2010-12-23 Gernot Münster , Tobias Sudmann

The problem of unphysical zero modes in lattice QCD with Wilson fermions can be solved in a clean way by including a mass term proportional to $i \psibar \gamma_5 \tau^3 \psi$ in the standard lattice theory with Nf=2 mass degenerate Wilson…

High Energy Physics - Lattice · Physics 2015-06-25 Roberto Frezzotti , Pietro Antonio Grassi , Stefan Sint , Peter Weisz

In this talk we give an overview of the 3D phase diagram of two-flavour non-zero temperature lattice QCD with twisted-mass Wilson fermions and a tree-level Symanzik-improved gauge action. We present a first feasibility study at maximal…

Our aim is to compute the lower moments of the unpolarized and polarized deep-inelastic structure functions of the nucleon on the lattice. The theoretical basis of the calculation is the operator product expansion. To construct operators…

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

We analytically derive a decomposition of the lattice fermion determinant for Wilson's Dirac operator with chemical potential into winding sectors, i.e., factors with a fixed number of quarks. Dividing the lattice into four domains, the…

High Energy Physics - Lattice · Physics 2009-01-01 Julia Danzer , Christof Gattringer

We present the status of a lattice calculation for the K-->pipi matrix elements of the (delta S=1) effective weak Hamiltonian, directly with two pion in the final state. We study the energy shift of two pion in a finite volume both in the…

High Energy Physics - Lattice · Physics 2012-08-27 Ph. Boucaud , V. Gimenez , C. J. D. Lin , V. Lubicz , G. Martinelli , M. Papinutto , F. Rapuano , C. T. Sachrajda , : , S. P. Qcd R. collaboration

Nucleon structure functions can be observed in Deep Inelastic Scattering experiments, but it is an outstanding challenge to confront them with fully non-perturbative QCD results. For this purpose we investigate the product of…

High Energy Physics - Lattice · Physics 2010-11-05 W. Bietenholz , N. Cundy , M. Goeckeler , R. Horsley , H. Perlt , D. Pleiter , P. E. L. Rakow , G. Schierholz , A. Schiller , T. Streuer , J. M. Zanotti

The phase structure of lattice QCD with two flavors and Wilson fermions is studied analytically. At $\beta=0$ we obtain rigorous lower and upper bounds for the critical hopping parameter $k_c(0)$ from a convergent hopping parameter…

High Energy Physics - Lattice · Physics 2009-09-25 A. Galli

We find the leading electroweak corrections to the Lagrangians of heavy-quark effective theory and nonrelativistic QCD. These corrections appear in the Wilson coefficients of the two- and four-quark operators and are considered here at…

High Energy Physics - Phenomenology · Physics 2023-06-06 B. Assi , B. A. Kniehl , J. Soto

In this contribution, a first look at simulations using maximally twisted mass Wilson fermions at the physical point is presented. A lattice action including clover and twisted mass terms is presented and the Monte Carlo histories of one…

We present the current status of our lattice QCD determination of the charm quark mass using $N_\mathrm{f}=2+1$ dynamical, non-perturbatively $\mathrm{O}(a)$ improved Wilson fermions. A subset of CLS ensembles with five different lattice…

High Energy Physics - Lattice · Physics 2019-09-13 Jochen Heitger , Fabian Joswig , Simon Kuberski