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Related papers: HMC algorithm for two-flavour lattice QCD: Schwarz…

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We investigate the low-lying eigenvalues of the improved Wilson-Dirac operator in the Schroedinger functional with two dynamical quark flavors. At a lattice spacing of approximately 0.1 fm we find more very small eigenvalues than in the…

High Energy Physics - Lattice · Physics 2009-11-10 M. Della Morte , R. Hoffmann , F. Knechtli , U. Wolff

We study the hadronic spectrum in quenched lattice QCD using an improved Wilson fermion action (Hamber-Wu(1983),Eguchi-Kawamoto(1984)) at $\beta= 5.7$ and $\beta =6.0$. We find a systematic reduction of the finite spacing effects compared…

High Energy Physics - Lattice · Physics 2009-10-22 M. -P. Lombardo , G. Parisi , A. Vladikas

We study and simulate N=2 supersymmetric Wess-Zumino models in one and two dimensions. For any choice of the lattice derivative, the theories can be made manifestly supersymmetric by adding appropriate improvement terms corresponding to…

High Energy Physics - Lattice · Physics 2008-11-26 Georg Bergner , Tobias Kaestner , Sebastian Uhlmann , Andreas Wipf

We present a method for formulating gauge theories of chiral fermions in lattice field theory. The method makes use of a Wilson mass to remove doublers. Gauge invariance is then restored by modifying the theory in two ways: the magnitude of…

High Energy Physics - Lattice · Physics 2009-10-28 Geoffrey T. Bodwin

We discuss the lattice formulation of gauge theories with fermions in arbitrary representations of the color group, and present the implementation of the RHMC algorithm for simulating dynamical Wilson fermions. A first dataset is presented…

High Energy Physics - Lattice · Physics 2010-01-21 Luigi Del Debbio , Agostino Patella , Claudio Pica

We present preliminary results of the PACS-CS project which simulates 2+1 flavor lattice QCD toward the physical point with the nonperturbatively O(a)-improved Wilson quark action and the Iwasaki gauge action. Calculations are carried out…

High Energy Physics - Lattice · Physics 2009-04-14 Yoshinobu Kuramashi

There has been much recent progress in the understanding and reduction of the computational cost of the Hybrid Monte Carlo algorithm for Lattice QCD as the quark mass parameter is reduced. In this letter we present a new solution to this…

High Energy Physics - Lattice · Physics 2008-11-26 M. A. Clark , A. D. Kennedy

In the Wilson's lattice formulation of QCD, a fermionic Fock space of states can be explicitly built at each time slice using canonical creation and annihilation operators. The partition function $Z$ is then represented as the trace of the…

High Energy Physics - Lattice · Physics 2022-09-21 Sergio Caracciolo , Mauro Pastore

We present an update on the ongoing calculations by the Fermilab Lattice, HPQCD, and MILC Collaboration of the leading-order (in electromagnetism) hadronic vacuum polarization contribution to the anomalous magnetic moment of the muon. Our…

We present results of a lattice simulation of quantum chromodynamics with two degenerate flavors of dynamic Wilson fermions at $6/g^2=5.3$ at each of two dynamical fermion hopping parameters, $\kappa=0.1670$ and 0.1675, corresponding to…

High Energy Physics - Lattice · Physics 2009-10-22 K. M. Bitar

We review the recent progress in new lattice fermion formulations. We focus on the following three types which have possibility of improving lattice simulations. (1) Flavored-mass fermions are a generalization of Wilson fermions with…

High Energy Physics - Lattice · Physics 2012-12-21 Tatsuhiro Misumi

Domain decomposition methods are among the most efficient for solving sparse linear systems of equations. Their effectiveness relies on a judiciously chosen coarse space. Originally introduced and theoretically proved to be efficient for…

Numerical Analysis · Mathematics 2022-01-10 Hussam Al Daas , Pierre Jolivet , Tyrone Rees

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

I describe a method that places the fermion fields and the gauge fields on different lattice spacings during the Hybrid Monte Carlo generation of Ginsparg-Wilson dynamical ensembles. The idea is motivated by Wilson's formulation of the…

High Energy Physics - Lattice · Physics 2010-11-05 Nigel Cundy

A lot of effort in lattice simulations over the last years has been devoted to studies of the QCD deconfinement transition. Most state-of-the-art simulations use rooted staggered fermions, while Wilson fermions are affected by large…

High Energy Physics - Lattice · Physics 2011-01-27 Bastian B. Brandt , Owe Philipsen , Hartmut Wittig , Lars Zeidlewicz

The Adaptive Aggregation-based Domain Decomposition Multigrid method (arXiv:1303.1377) is extended for two degenerate flavors of twisted mass fermions. By fine-tuning the parameters we achieve a speed-up of the order of hundred times…

High Energy Physics - Lattice · Physics 2016-12-21 Constantia Alexandrou , Simone Bacchio , Jacob Finkenrath , Andreas Frommer , Karsten Kahl , Matthias Rottmann

The pseudofermion action of the Hybrid Monte Carlo (HMC) algorithm for dynamical fermions is modified to directly incorporate Incomplete LU (ILU) factorisation. This reduces the stochastic noise and allows a larger molecular dynamics…

High Energy Physics - Lattice · Physics 2007-05-23 Mike Peardon

In the search for a composite Higgs boson in walking technicolor models, many flavor QCD, in particular with $N_f=8$, is an attractive candidate, and has been found to have a composite flavor-singlet scalar as light as the pion. Based on…

We make the first calculation in lattice QCD of two-photon decays of mesons. Working in the charmonium sector, using the LSZ reduction to relate a photon to a sum of hadronic vector eigenstates, we compute form-factors in both the…

High Energy Physics - Phenomenology · Physics 2008-11-26 Jozef J. Dudek , Robert G. Edwards

We define a sparse hermitian lattice Dirac matrix, $H$, coupling $2n+1$ Dirac fermions. When $2n$ fermions are integrated out the induced action for the last fermion is a rational approximation to the hermitian overlap Dirac operator. We…

High Energy Physics - Lattice · Physics 2009-10-31 R. Narayanan , H. Neuberger