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Related papers: SSOR preconditioning in simulations of the QCD Sch…

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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

A parallelizable SSOR preconditioning scheme for Krylov subspace iterative solvers in lattice QCD applications involving Wilson fermions is presented. In actual Hybrid Monte Carlo and quark propagator calculations it helps to reduce the…

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

The Schr\"odinger Functional (quantum/lattice field theory with Dirichlet boundary conditions) is a powerful tool in the non-perturbative improvement and for the study of other aspects of lattice QCD. Here we adapt it to improved gluon and…

High Energy Physics - Lattice · Physics 2009-10-30 T. R. Klassen

Lattice simulations on SU(2) and SU(3) gauge theories with matter fields in the fundamental, adjoint and two index symmetric representations are needed to determine if these theories are near or within the conformal window as required for…

High Energy Physics - Lattice · Physics 2015-06-03 T. Karavirta , K. Rummukainen , K. Tuominen

We explain how masses and matrix elements can be computed in lattice QCD using Schr"odinger functional boundary conditions. Numerical results in the quenched approximation demonstrate that good precision can be achieved. For a statistical…

High Energy Physics - Lattice · Physics 2015-06-25 Marco Guagnelli , Jochen Heitger , Rainer Sommer , Hartmut Wittig

We present a parallelizable SSOR preconditioning scheme for Krylov subspace iterative solvers which proves to be efficient in lattice QCD applications involving Wilson fermions. Our preconditioner is based on a locally lexicographic…

High Energy Physics - Lattice · Physics 2009-10-28 S. Fischer , A. Frommer , U. Glaessner , Th. Lippert , G. Ritzenhoefer , K. Schilling

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

Using the Schr\"odinger functional we have computed a variety of renormalized on-shell correlation functions to one-loop order of perturbation theory. By studying their approach to the continuum limit we have determined the O($a$)…

High Energy Physics - Lattice · Physics 2009-10-30 Stefan Sint , Peter Weisz

We present a scaling study of lattice QCD with O(a) improved Wilson fermions and a chirally twisted mass term. In order to get precise results with a moderate computational effort, we have considered a system of physical size of 0.75^3 *…

High Energy Physics - Lattice · Physics 2009-10-31 M. Della Morte , R. Frezzotti , J. Heitger , S. Sint

We review recent work by the ALPHA and UKQCD Collaborations where masses and matrix elements were computed in lattice QCD using Schr\"odinger functional boundary conditions and where the strange quark mass was determined in the quenched…

High Energy Physics - Lattice · Physics 2015-06-25 Joyce Garden , Marco Guagnelli , Jochen Heitger , Rainer Sommer , Hartmut Wittig

Similarly to the interaction lagrangian, the possible boundary conditions in quantum field theories on space-time manifolds with boundaries are strongly constrained by the symmetry and scaling properties of the theory. Based on this general…

High Energy Physics - Lattice · Physics 2009-11-11 Martin Lüscher

The chirally rotated Schroedinger functional provides a test bed for universality and automatic O(a) improvement. We here report on extensive quenched simulations of lattice QCD with Wilson quarks in the massless limit. We demonstrate that,…

High Energy Physics - Lattice · Physics 2010-12-14 Bjorn Leder , Stefan Sint

We compute the Schroedinger functional (SF) for the case of lattice QCD with Wilson fermions (with and without SW improvement) at two-loop order in lattice perturbation theory. This allows us to extract the three-loop beta-function in the…

High Energy Physics - Lattice · Physics 2008-11-26 Achim Bode , Peter Weisz , Ulli Wolff

SSOR preconditioning of fermion matrix inversions which is parallelized using a locally-lexicographic lattice sub-division, has been shown to be very efficient for standard Wilson fermions. We demonstrate here the power of this method for…

High Energy Physics - Lattice · Physics 2009-10-31 N. Eicker , W. Bietenholz , A. Frommer , Th. Lippert , B. Medeke , K. Schilling

The scaling of the Schr"odinger functional coupling is studied numerically and perturbatively for an SU(3) lattice gauge field coupled to an O(a) improved bosonic spinor field. This corresponds to QCD with minus two light flavours and is…

High Energy Physics - Lattice · Physics 2015-06-25 Bernd Gehrmann , Juri Rolf , Stefan Kurth , Ulli Wolff

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 perturbatively determine O($a$) boundary improvement coefficients at 1-loop for the Schr\"odinger Functional coupling with improved gauge actions. These coefficients are required to implement the 1-loop O($a$) improvement in full QCD…

High Energy Physics - Lattice · Physics 2015-06-25 Shinji Takeda , Sinya Aoki , Kiyotomo Ide

I derive the equation of motion in molecular dynamics for doing full lattice QCD simulations with clover quarks. The even-odd preconditioning technique, expected to significantly reduce the computational effort, is further developed for the…

High Energy Physics - Lattice · Physics 2009-10-28 Xiang-Qian Luo

Lattice QCD simulations at small lattice spacings and quark masses close to their physical values are technically challenging. In particular, the simulations can get trapped in the topological charge sectors of field space or may run into…

High Energy Physics - Lattice · Physics 2015-06-05 Martin Lüscher , Stefan Schaefer

A modified formulation of the Schr\"odinger functional (SF) is proposed. In the continuum it is related to the standard SF by a non-singlet chiral field rotation and therefore referred to as the chirally rotated SF ($\chi$SF). On the…

High Energy Physics - Lattice · Physics 2011-03-21 Stefan Sint
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