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Related papers: Physics results from dynamical overlap fermion sim…

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I review the recent progress in lattice QCD, which will be useful in heavy quark physics in the near future. Reviewing the theoretical developments in lattice QCD first, I focus our recent unquenched QCD with dynamical overlap fermion as…

High Energy Physics - Phenomenology · Physics 2009-06-15 Tetsuya Onogi

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 present first, exploratory results of a hybrid Monte-Carlo algorithm for dynamical, n_f=2, four-dimensional QCD with overlap fermions. As expected, the computational requirements are typically two orders of magnitude larger for the…

High Energy Physics - Lattice · Physics 2010-02-03 Z. Fodor , S. D. Katz , K. K. Szabo

Overlap fermions implement exact chiral symmetry on the lattice and are thus an appropriate tool for investigating the chiral and topological structure of the QCD vacuum. We study various chiral and topological aspects on…

High Energy Physics - Lattice · Physics 2009-11-11 E. -M. Ilgenfritz , K. Koller , Y. Koma , G. Schierholz , T. Streuer , V. Weinberg

A certain U(1) model in 2 dimensions, describing four right handed unit charged Weyl fermions interacting with one doubly charged left handed Weyl fermion, is exactly soluble and has massless Majorana-Weyl composites. Instanton induced…

High Energy Physics - Lattice · Physics 2009-10-30 Yoshio Kikukawa , Herbert Neuberger

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

As one approaches the continuum limit, $QCD$ systems, investigated via numerical simulations, remain trapped in sectors of field space with fixed topological charge. As a consequence the numerical studies of physical quantities may give…

High Energy Physics - Lattice · Physics 2016-08-02 Alessandro Laio , Guido Martinelli , Francesco Sanfilippo

Finite-volume modifications of the two-flavor chiral phase diagram are investigated within an effective quark-meson model in various mean-field approximations. The role of vacuum fluctuations and boundary conditions, their influence on…

High Energy Physics - Phenomenology · Physics 2016-11-14 Ana Juričić , Bernd-Jochen Schaefer

We present numerical results for the 2-flavour Schwinger model with dynamical chiral lattice fermions. We insert an approximately chiral hypercube Dirac operator into the overlap formula to construct the overlap hypercube operator. This is…

High Energy Physics - Lattice · Physics 2012-04-26 Wolfgang Bietenholz , Ivan Hip , Stanislav Shcheredin , Jan Volkholz

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

We investigate the realization of chiral symmetry in the vicinity of the deconfinement transition in quenched QCD using overlap fermions. Via the index theorem obeyed by the overlap fermions, we gain insight into the behavior of topology at…

High Energy Physics - Lattice · Physics 2015-06-25 Robert G. Edwards , Urs M. Heller , Joe Kiskis , Rajamani Narayanan

We discuss latest results of lattice QCD simulations with dynamical fermions. Special emphasis is paid to the subjects of the static quark potential, the light hadron spectrum, $\Upsilon$ spectrum, and the pion-nucleon-sigma term.

High Energy Physics - Lattice · Physics 2009-10-30 S. Guesken

We present results of lattice computations using overlap fermions on a twisted mass background. $N_f=2$ full QCD gauge configurations have been produced by the ETM Collaboration with very light pions (down to less than 300 MeV), with small…

High Energy Physics - Lattice · Physics 2009-04-14 Nicolas Garron , Luigi Scorzato

In the last few years, numerical simulations of QCD on the lattice have reached a new level of accuracy. A wide range of thermodynamic quantities is now available in the continuum limit and for physical quark masses. This allows a…

High Energy Physics - Lattice · Physics 2018-07-25 Claudia Ratti

We study quenched QCD just above the phase transition temperature using overlap Fermions. Exact zero modes of the overlap operator are localized. Chiral symmetry is restored, as indicated by the behavior of the chiral condensate after…

High Energy Physics - Lattice · Physics 2015-06-25 R. V. Gavai , Sourendu Gupta , R. Lacaze

Boson, fermion, and super oscillators and (statistical) mechanism of cosmological constant; finite approximation of the zeta-function and fermion factorization of the bosonic statistical sum considered.

General Physics · Physics 2018-11-14 Nugzar Makhaldiani

The impact of dynamical fermions on the vacuum structure of QCD is explored. Of particular interest is the topological charge correlator, $<q(x) q(0) >$, where negative values at small $x$ reveal a sign-alternating layered structure to the…

High Energy Physics - Lattice · Physics 2008-11-26 Peter J. Moran , Derek B. Leinweber

A residual gauge symmetry, exhibited by light-front gauge theories quantized in a finite volume, is analyzed at the quantum level. Unitary operators, which implement the symmetry, transform the trivial Fock vacuum into an infinite set of…

High Energy Physics - Theory · Physics 2009-10-31 L. Martinovic

We study the effect of finite temperatures and Fermion density on the effective pseudo-scalar-photon vertex induced by the triangle diagram. The manifestly covariant calculations show that when the pseudo-scalar mass is much less than the…

High Energy Physics - Phenomenology · Physics 2007-05-23 Sourendu Gupta , S. N. Nayak

Overlap fermions have an exact chiral symmetry on the lattice and are thus an appropriate tool for investigating the chiral and topological structure of the QCD vacuum. We study various chiral and topological aspects of quenched gauge field…

High Energy Physics - Lattice · Physics 2008-11-26 E. -M. Ilgenfritz , K. Koller , Y. Koma , G. Schierholz , T. Streuer , V. Weinberg