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Related papers: A lattice Dirac operator for QCD with light dynami…

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It has been shown recently that Dirac operators satisfying the Ginsparg-Wilson relation provide a solution of the chirality problem in QCD at finite lattice spacing. We discuss different ways to construct these operators and their…

High Energy Physics - Lattice · Physics 2011-07-19 Ferenc Niedermayer

We combine a pair of independent Weyl fermions to compose a Dirac fermion on the four-dimensional Euclidean lattice. The obtained Dirac operator is antihermitian and does not reproduce anomaly under the usual chiral transformation. To…

High Energy Physics - Lattice · Physics 2007-05-23 Takanori Sugihara

We briefly review the overlap formalism for chiral gauge theories, the overlap Dirac operator for massless fermions and its connection to domain wall fermions. We describe properties of the overlap Dirac operator, and methods to implement…

High Energy Physics - Lattice · Physics 2007-05-23 Robert G. Edwards , Urs M. Heller , Joe Kiskis , Rajamani Narayanan

We simulate two dynamical, mass degenerate light quarks on 16^3x32 lattices with a spatial extent of 2.4 fm using the Chirally Improved Dirac operator. The simulation method, the implementation of the action and signals of equilibration are…

High Energy Physics - Lattice · Physics 2009-11-06 Christof Gattringer , Christian Hagen , C. B. Lang , Markus Limmer , Daniel Mohler , Andreas Schäfer

We construct a lattice Dirac operator of overlap type that describes the propagation of a Dirac fermion in an external gravitational field. The local Lorentz symmetry is manifestly realized as a lattice gauge symmetry, while it is believed…

High Energy Physics - Lattice · Physics 2009-11-11 Masashi Hayakawa , Hiroto So , Hiroshi Suzuki

We use a chiral random matrix model to investigate the effects of massive quarks on the distribution of eigenvalues of QCD inspired Dirac operators. Kalkreuter's lattice analysis of the spectrum of the massive (hermitean) Dirac operator for…

High Energy Physics - Phenomenology · Physics 2009-10-28 Jerzy Jurkiewicz , Maciej A. Nowak , Ismail Zahed

We discuss how to formulate Dirac fermion operator on a finite lattice such that it can provide a nonperturbative regularization for massless fermion interacting with a background gauge field.

High Energy Physics - Lattice · Physics 2011-02-16 Ting-Wai Chiu

We compute fermionic observables relevant to the study of chiral symmetry in quenched QCD using the Overlap-Dirac operator for a wide range of the fermion mass. We use analytical results to disentangle the contribution from exact zero modes…

High Energy Physics - Lattice · Physics 2009-10-31 Robert G. Edwards , Urs M. Heller , Rajamani Narayanan

In a local gauge-invariant theory with massless Dirac fermions a symmetry of the Lorentz-invariant fermion charge is larger than a symmetry of the Lagrangian as a whole. While the Dirac Lagrangian exhibits only a chiral symmetry, the…

High Energy Physics - Phenomenology · Physics 2019-01-14 L. Ya. Glozman

We examine quenched chiral logarithms in lattice QCD with overlap Dirac quark. For 100 gauge configurations generated with the Wilson gauge action at $ \beta = 5.8 $ on the $ 8^3 \times 24 $ lattice, we compute quenched quark propagators…

High Energy Physics - Lattice · Physics 2011-02-16 Ting-Wai Chiu , Tung-Han Hsieh

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

We present a detailed study of the interplay between chiral symmetry and spectral properties of the Dirac operator in lattice gauge theories. We consider, in the framework of the Schwinger model, the fixed point action and a fermion action…

High Energy Physics - Lattice · Physics 2009-10-31 F. Farchioni , I. Hip , C. B. Lang , M. Wohlgenannt

We reconsider constraints on the eigenvalue density of the Dirac operator in the chiral symmetric phase of 2 flavor QCD at finite temperature. To avoid possible ultra-violet(UV) divergences, we work on a lattice, employing the overlap Dirac…

High Energy Physics - Lattice · Physics 2013-05-30 Sinya Aoki , Hidenori Fukaya , Yusuke Taniguchi

Close to the continuum the lattice spacing affects the smallest eigenvalues of the Wilson Dirac operator in a very specific manner determined by the way in which the discretization breaks chiral symmetry. These effects can be computed…

High Energy Physics - Lattice · Physics 2012-11-09 K. Splittorff

We report on the two-flavor QCD simulation in the epsilon-regime using the overlap fermion formulation. Sea quark mass is reduced to ~ 2 MeV on a 16^3x32 lattice with the lattice spacing ~ 0.11fm. Topological charge is fixed at Q=0. We…

High Energy Physics - Lattice · Physics 2008-11-26 JLQCD collaboration , H. Fukaya , S. Hashimoto , K. Kanaya , T. Kaneko , H. Matsufuru , K. Ogawa , M. Okamoto , T. Onogi , N. Yamada

Lattice QCD using fermions whose Dirac operator obeys the Ginsparg-Wilson relation, is perhaps the best known formulation of QCD with a finite cutoff. It reproduces all the low energy QCD phenomenology associated with chiral symmetry at…

High Energy Physics - Lattice · Physics 2016-08-25 Shailesh Chandrasekharan

A quantitative study of the effects of dynamical chiral symmetry breaking on the mass generation of the low-lying hadrons in a dynamical lattice QCD simulation is presented. The evolution of light hadron masses upon increasing the number of…

High Energy Physics - Lattice · Physics 2014-01-24 M. Denissenya , L. Ya. Glozman

This talk presents a lattice study of spontaneous chiral symmetry breaking performed by the JLQCD and TWQCD collaborations with dynamical overlap fermions. Our lattice configurations are generated in a fixed topological sector. Since finite…

High Energy Physics - Lattice · Physics 2019-08-14 Hidenori Fukaya

A chiral fermion action allows one to do very clean studies of chiral symmetry breaking in QCD. I will briefly describe how to compute with the overlap action (relatively) cheaply, and then turn to physics: Low modes of the Dirac operator…

High Energy Physics - Lattice · Physics 2007-05-23 Thomas DeGrand

We propose improved estimators to compute the reweighting factors which are needed for lattice QCD calculations that rely on twisted-mass reweighting for the light quark contribution and the Rational Hybrid Monte Carlo (RHMC) algorithm for…

High Energy Physics - Lattice · Physics 2024-03-19 Simon Kuberski