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Related papers: Large N reduction with overlap fermions

200 papers

In QCD chiral symmetry is explicitly broken by quark masses, the effect of which can be described reliably by chiral perturbation theory. Effects of explicit chiral symmetry breaking by the lattice regularisation of the Dirac operator,…

High Energy Physics - Lattice · Physics 2011-01-27 Nigel Cundy , Tony Kennedy , 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 apply different types of overlap operators in quenched QCD simulations to compute the zero mode contribution to the pseudo-scalar correlator. In particular we use the conventional Neuberger Dirac operator and the overlap hypercube Dirac…

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

Chiral symmetry is a key to investigating quantum physics, from condensed matter to particle physics. We propose a novel way of realizing a chiral fermion, known as the overlap-Dirac operator, without explicitly calculating the low modes of…

High Energy Physics - Lattice · Physics 2022-04-05 Yuki Nagai , Akio Tomiya

In this work we attempt to determine the mass anomalous dimension of the SU(N) gauge theory with two Dirac fermions in the adjoint representation, in the limit of large N. The method uses the mode number of the Dirac operator, as done in…

High Energy Physics - Phenomenology · Physics 2012-10-30 Liam Keegan

We compute lattice renormalisation constants of local bilinear quark operators for overlap fermions and improved gauge actions. Among the actions we consider are the Symanzik, L\"uscher-Weisz, Iwasaki and DBW2 gauge actions. The results are…

High Energy Physics - Lattice · Physics 2008-11-26 R. Horsley , H. Perlt , P. E. L. Rakow , G. Schierholz , A. Schiller

We present simulation results for the 2-flavour Schwinger model with dynamical Ginsparg-Wilson fermions. Our Dirac operator is constructed by inserting an approximately chiral hypercube operator into the overlap formula, which yields the…

High Energy Physics - Lattice · Physics 2008-11-26 Jan Volkholz , Wolfgang Bietenholz , Stanislav Shcheredin

In this preliminary work, I provide the outline of an argument (leaving the full proof to a future publication) that there exists a valid renormalization group blocking transformation which converts the continuum fermion action into a…

High Energy Physics - Lattice · Physics 2010-01-21 Nigel Cundy

The chiral Jacobian, which is defined with Neuberger's overlap Dirac operator of the lattice fermion, is explicitly evaluated in the continuum limit without expanding it in the gauge coupling constant. Our calculational scheme is simple and…

High Energy Physics - Theory · Physics 2009-10-31 Hiroshi Suzuki

We perform a comparative study of the infrared properties of overlap and staggered fermions in QCD. We observe that the infrared spectrum of the APE/HYP improved staggered Dirac operator develops a four-fold near-degeneracy and is in…

High Energy Physics - Lattice · Physics 2009-11-10 S. Dürr , Ch. Hoelbling , U. Wenger

New extended interpolating operators made of quenched three dimensional fermions are introduced in the context of lattice QCD. The mass of the 3D fermions can be tuned in a controlled way to find a better overlap of the extended operators…

High Energy Physics - Lattice · Physics 2018-11-28 Mauro Papinutto , Francesco Scardino , Stefan Schaefer

I review the lattice formulations of vector-like gauge theories (e.g. QCD) with domain-wall/overlap fermions, and discuss how to optimize the chiral symmetry for any finite $ N_s $ (sites in the fifth dimension). In this formulation, quark…

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

In odd dimensions the lattice overlap formalism is simpler than in even dimensions. Masslessness of fermions can still be preserved without fine tuning and gauge invariance without gauge averaging can be maintained, although, sometimes,…

High Energy Physics - Lattice · Physics 2009-10-30 Y. Kikukawa , H. Neuberger

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

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

I describe a recent calculation (by me, Hoffmann, Liu, and Schaefer) of the chiral condensate in one-flavor QCD using numerical simulations with overlap fermions. The condensate is extracted by fitting the distribution of low lying…

High Energy Physics - Lattice · Physics 2008-11-26 Thomas DeGrand

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

We report on an ongoing project to parametrize the Fixed-Point Dirac operator for massless quarks, using a very general construction which has arbitrarily many fermion offsets and gauge paths, the complete Clifford algebra and satisfies all…

High Energy Physics - Lattice · Physics 2009-10-31 P. Hasenfratz , S. Hauswirth , K. Holland , T. Jorg , F. Niedermayer , U. Wenger

We study the large-N volume reduction of QCD with adjoint quarks regularized on the lattice. Specifically, we use Wilson fermions, and while our d-dimensional lattice has (d-1) infinite dimensions, the remaining direction is reduced to a…

High Energy Physics - Lattice · Physics 2009-07-24 Barak Bringoltz

I review some of the things we have learned about large N gauge theories (and QCD at N=oo) from lattice calculations in recent years. I point to some open problems.

High Energy Physics - Lattice · Physics 2010-01-21 Michael Teper