English
Related papers

Related papers: Constructing Improved Overlap Fermions in QCD

200 papers

The overlap operator is a lattice discretization of the Dirac operator of quantum chromodynamics, the fundamental physical theory of the strong interaction between the quarks. As opposed to other discretizations it preserves the important…

High Energy Physics - Lattice · Physics 2014-10-28 James Brannick , Andreas Frommer , Karsten Kahl , Björn Leder , Matthias Rottmann , Artur Strebel

We discuss a proposal for the construction of lattice QCD with gauge action, fermionic action, theta-term, and the operators all based on the lattice Dirac operator D with exact chiral symmetry. The simplest regularization of this type uses…

High Energy Physics - Lattice · Physics 2008-11-26 Ivan Horvath

We present results from simulations of two flavors of dynamical overlap fermions on 8^4 lattices at three values of the sea quark mass and a lattice spacing of about 0.16 fm. We measure the topological susceptibility and the chiral…

High Energy Physics - Lattice · Physics 2009-11-11 Thomas DeGrand , Stefan Schaefer

The application of Random Matrix Theory to the Dirac operator of QCD yields predictions for the probability distributions of the lowest eigenvalues. We measured Dirac operator spectra using massless overlap fermions in quenched QCD at…

High Energy Physics - Lattice · Physics 2009-11-10 S. Shcheredin , W. Bietenholz , T. Chiarappa , K. Jansen , K. -I. Nagai

It was recently proposed by the second author to consider lattice formulations of QCD in which complete actions, including the gauge part, are built explicitly from a given Dirac operator D. In a simple example of such theory, the gauge…

High Energy Physics - Lattice · Physics 2008-11-26 Andrei Alexandru , Ivan Horvath , Keh-Fei Liu

We compute the ratio $\Lambda_L/\Lambda_{\bar{MS}}$ between the scale parameter $\Lambda_L$, associated with a lattice formulation of QCD using the overlap-Dirac operator, and $\Lambda_{\bar{MS}}$ of the $\bar{\rm MS}$ renormalization…

High Energy Physics - Lattice · Physics 2009-10-31 C. Alexandrou , H. Panagopoulos , E. Vicari

We derive the effective action of the light fermion field of the domain-wall fermion, which is referred as q(x) and \bar q(x) by Furman and Shamir. The inverse of the effective Dirac operator turns out to be identical to the inverse of the…

High Energy Physics - Lattice · Physics 2007-05-23 Yoshio Kikukawa

This thesis is dedicated to explore the feasibility of numerical calculations in the $\epsilon$--regime of QCD for the extraction of physical information. We apply two formulations of the Ginsparg-Wilson fermions the Neuberger operator and…

High Energy Physics - Lattice · Physics 2007-05-23 S. Shcheredin

Strange quark content of the nucleon is calculated in dynamical lattice QCD employing the overlap fermion formulation. For this quantity, exact chiral symmetry guaranteed by the Ginsparg-Wilson relation is crucial to avoid large…

High Energy Physics - Lattice · Physics 2011-06-21 JLQCD collaboration , K. Takeda , S. Aoki , S. Hashimoto , T. Kaneko , J. Noaki , T. Onogi

We present preliminary results for the D_s meson spectroscopy study on the 2+1 flavour domain wall fermion lattice configurations, generated with the Iwasaki gauge action at beta=2.13 by the RBC-UKQCD collaboration. The simulations are on…

High Energy Physics - Lattice · Physics 2008-11-26 Chris Allton , Chris Maynard , Aurora Trivini , Robert Tweedie

We compare the behavior of different lattice Dirac operators in gauge backgrounds which are lattice discretizations of a classical instanton. In particular we analyze the standard Wilson operator, a chirally improved Dirac operator and the…

High Energy Physics - Lattice · Physics 2008-11-26 Christof Gattringer , Meinulf Göckeler , C. B. Lang , P. E. L. Rakow , Andreas Schäfer

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

A perturbative study of a general class of lattice Dirac operators is reported, which is based on an algebraic realization of the Ginsparg-Wilson relation in the form $\gamma_{5}(\gamma_{5}D)+(\gamma_{5}D)\gamma_{5} =…

High Energy Physics - Lattice · Physics 2016-09-01 Kazuo Fujikawa , Masato Ishibashi

A simulation of quenched QCD with the overlap Dirac operator has been completed using 100 Wilson gauge configurations at beta = 6 on an 18^3 x 64 lattice and at beta = 5.85 on a 14^3 x 48 lattice, both in Landau gauge. We present results…

We use a continued fraction expansion of the sign-function in order to obtain a five dimensional formulation of the overlap lattice Dirac operator. Within this formulation the inverse of the overlap operator can be calculated by a single…

High Energy Physics - Lattice · Physics 2015-06-25 A. Borici , A. D. Kennedy , B. J. Pendleton , U. Wenger

I report the status of the dynamical overlap fermion project by the JLQCD and TWQCD collaborations. So far, the simulations have been completed with two flavors of overlap sea quarks in a wide range of sea quark mass corresponding the…

High Energy Physics - Lattice · Physics 2019-08-14 Hideo Matsufuru

We study the eigenvalues of Dirac operators in QCD with two mass degenerate dynamical fermions. The gauge configurations have been obtained with HMC and the so-called Chirally Improved fermionic action. We compare eigenvalues obtained for…

High Energy Physics - Lattice · Physics 2009-04-14 Martina Joergler , C. B. Lang

In this talk I propose a new computational scheme with overlap fermions and a fast algorithm to invert the corresponding Dirac operator.

High Energy Physics - Lattice · Physics 2015-06-25 A. Borici

We present the first study of the charmonium spectrum using overlap fermions, on quenched configurations. Simulations are performed on $16^3 \times 72$ lattices, with Wilson gauge action at $\beta$ = 6.3345. We demonstrate that we have…

High Energy Physics - Lattice · Physics 2008-11-26 S. Tamhankar , A. Alexandru , Y. Chen , S. J. Dong , T. Draper , I. Horvath , F. X. Lee , K. F. Liu , N. Mathur , J. B. Zhang

A numerical investigation of time-separated charge overlap measurements is carried out for the pion in the context of lattice QCD using smeared Wilson fermions. The evolution of the charge distribution function is examined and the expected…

High Energy Physics - Lattice · Physics 2009-10-22 Walter Wilcox
‹ Prev 1 3 4 5 6 7 10 Next ›