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Related papers: Towards the topological susceptibility with overla…

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We estimate the quark-mass dependence of the topological susceptibility with dynamical overlap and clover fermions. Unquenching effects on the susceptibility turn out to be well approximated by a reweighting of a quenched ensemble with a…

High Energy Physics - Lattice · Physics 2015-06-25 Tamas G. Kovacs

We investigate topology in lattice simulations of QCD with two flavours of dynamical Wilson fermions. At various sea quark masses we find reasonable agreement between results for the topological charge from fermionic and gluonic…

High Energy Physics - Lattice · Physics 2008-11-26 Gunnar S. Bali , Norbert Eicker , Thomas Lippert , Hartmut Neff , Boris Orth , Klaus Schilling , Thorsten Struckmann , Jochen Viehoff

We report on simulation results with overlap hypercube fermions (overlap HF) - a type of exactly chiral lattice fermions - and their link to chiral perturbation theory. We first sketch the construction of the overlap HF and discuss its high…

High Energy Physics - Lattice · Physics 2011-04-11 W. Bietenholz , S. Shcheredin

We perform dynamical QCD simulations with $n_f=2$ overlap fermions by hybrid Monte-Carlo method on $6^4$ to $8^3\times 16$ lattices. We study the problem of topological sector changing. A new method is proposed which works without…

High Energy Physics - Lattice · Physics 2009-11-11 G. I. Egri , Z. Fodor , S. D. Katz , K. K. Szabo

We discuss properties of thermal Quantum Chromodynamics obtained by means of lattice simulations with overlap fermions. This fermion discretisation preserves chiral symmetry at finite lattice spacing. We present details of the formulation…

High Energy Physics - Lattice · Physics 2025-10-30 Z. Fodor , A. Yu. Kotov , T. G. Kovacs , K. K. Szabo

I apply a recently developed algorithm for reweighting simulations of lattice QCD from one quark mass to another to simulations performed with overlap fermions in the epsilon regime. I test it by computing the condensate from distributions…

High Energy Physics - Lattice · Physics 2009-01-08 Thomas DeGrand

The topological charge density and topological susceptibility are determined by multi-probing approximation using overlap fermions in quenched SU(3) gauge theory. Then we investigate the topological structure of the quenched QCD vacuum, and…

High Energy Physics - Lattice · Physics 2017-09-01 You-Hao Zou , Jian-Bo Zhang , Guang-Yi Xiong , Ying Chen , Chuan Liu , Yu-Bin Liu , Jian-Ping Ma

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

The overlap hypercube fermion is a variant of a chirally symmetric lattice fermion, which is endowed with a higher level of locality than the standard overlap fermion. We apply this formulation in quenched QCD simulations with light quarks.…

High Energy Physics - Lattice · Physics 2009-11-11 W. Bietenholz , S. Shcheredin

We summarize our recent investigations of lattice QCD with dynamical overlap fermions. We sketch algorithmic issues and our approach to solving them. We show our measurement of the topological susceptibility. We describe a computation of…

High Energy Physics - Lattice · Physics 2007-05-23 Stefan Schaefer , Thomas DeGrand

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

We address a long standing problem regarding topology in lattice simulations of QCD with unimproved Wilson fermions. Earlier attempt with unimproved Wilson fermions at \beta =5.6 to verify the suppression of topological susceptibility with…

High Energy Physics - Lattice · Physics 2015-05-30 Abhishek Chowdhury , Asit K. De , Sangita De Sarkar , A. Harindranath , Santanu Mondal , Anwesa Sarkar , Jyotirmoy Maiti

Knowledge of the derivative of the topological susceptibility at zero momentum is important for assessing the validity of the Witten-Veneziano formula for the eta' mass, and likewise for the resolution of the EMC proton spin problem. We…

High Energy Physics - Lattice · Physics 2015-03-17 Yoshiaki Koma , Ernst-Michael Ilgenfritz , Karl Koller , Miho Koma , Gerrit Schierholz , Thomas Streuer , Volker Weinberg

We study the topological charge and the topological susceptibility in lattice QCD with two degenerate flavors of naive Wilson fermions at two values of lattice spacings and different volumes, for a range of quark masses. Configurations are…

High Energy Physics - Lattice · Physics 2011-11-09 Abhishek Chowdhury , Asit K. De , Sangita De Sarkar , A. Harindranath , Santanu Mondal , Anwesa Sarkar , Jyotirmoy Maiti

We consider a recent proposal by Horv\'ath {\em et al.} to address the question whether topological charge fluctuations in QCD are instanton dominated via the response of fermions using lattice fermions with exact chiral symmetry, the…

High Energy Physics - Lattice · Physics 2014-11-17 Robert G. Edwards , Urs M. Heller

Chiral perturbation theory predicts that in quantum chromodynamics (QCD), light dynamical quarks suppress the gauge-field topological susceptibility of the vacuum. The degree of suppression depends on quark multiplicity and masses. It…

We present results of a hybrid Monte-Carlo algorithm for dynamical, $n_f=2$, four-dimensional QCD with overlap fermions. The fermionic force requires careful treatment, when changing topological sectors. The pion mass dependence of the…

High Energy Physics - Lattice · Physics 2009-11-10 Z. Fodor , S. D. Katz , K. K. Szabo

We investigate how the topological charge density in lattice QCD simulations is affected by violations of chiral symmetry caused by the fermion action. To this end we compare lattice configurations generated with a number of different…

High Energy Physics - Lattice · Physics 2012-01-10 Falk Bruckmann , Nigel Cundy , Florian Gruber , Thomas Lippert , Andreas Schäfer

The topological susceptibility is one of the few physical quantities that directly measure the properties of the QCD vacuum. Chiral perturbation theory predicts that in the small quark mass limit the topological susceptibility depends…

High Energy Physics - Lattice · Physics 2009-11-07 Anna Hasenfratz

We investigate how the topological charge density in lattice QCD simulations is affected by violations of chiral symmetry in different fermion actions. To this end we compare lattice configurations generated with a number of different…

High Energy Physics - Lattice · Physics 2012-01-10 Falk Bruckmann , Nigel Cundy , Florian Gruber , Thomas Lippert , Andreas Schäfer
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