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Related papers: Overlap Dirac operator at nonzero chemical potenti…

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We propose a lattice action including unphysical Wilson fermions with a negative mass m_0 of the order of the inverse lattice spacing. With this action, the exact zero mode of the hermitian Wilson-Dirac operator H_W(m_0) cannot appear and…

High Energy Physics - Lattice · Physics 2009-11-11 JLQCD collaboration , H. Fukaya , S. Hashimoto , K. -I. Ishikawa , T. Kaneko , H. Matsufuru , T. Onogi , N. Yamada

We investigate the spectral properties of the Wilson Dirac operator in quenched QCD in the microscopic regime. We distinguish the topological sectors using the index as determined by the Wilson flow method. Consequently, the distributions…

High Energy Physics - Lattice · Physics 2012-01-04 Albert Deuzeman , Urs Wenger , Jair Wuilloud

We compute the one-loop lattice renormalization of the two-quark operators $\bar{\psi} \Gamma \psi$, where $\Gamma$ denotes the generic Dirac matrix, for the lattice formulation of QCD using the overlap-Dirac operator. We also study the…

High Energy Physics - Lattice · Physics 2008-11-26 C. Alexandrou , E. Follana , H. Panagopoulos , E. Vicari

We present the results of an exploratory numerical study of two dimensional QCD with overlap fermions. We have performed extensive simulations for U(N_c) and SU(N_c) color groups with N_c=2, 3, 4 and coupling constants chosen to satisfy the…

High Energy Physics - Lattice · Physics 2009-11-07 F. Berruto , L. Giusti , C. Hoelbling , C. Rebbi

Lattice fermions obeying the Ginsparg-Wilson relation do correctly represent the physical properties related to chirality. This can be achieved by local fermions, which involve an infinite number of couplings, however. For practical…

High Energy Physics - Lattice · Physics 2017-08-23 W. Bietenholz

The Dirac equation with mass and axial chemical potential is solved analytically obtaining the mode spinors and corresponding projection operators giving the spectral representations of the principal conserved operators. In this framework,…

High Energy Physics - Theory · Physics 2025-06-24 Ion I. Cotaescu

The low energy eigenmodes of the continuum QCD Dirac operator are extended, but on the lattice, due to discretization effects, the Dirac operator can have localized eigenmodes. These non-physical modes can introduce strong lattice artifacts…

High Energy Physics - Lattice · Physics 2009-04-14 Anna Hasenfratz , Roland Hoffmann , Stefan Schaefer

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 compute Neuberger's overlap operator by the Lanczos algorithm applied to the Wilson-Dirac operator. Locality of the operator for quenched QCD data and its eigenvalue spectrum in an instanton background are studied.

High Energy Physics - Lattice · Physics 2011-07-19 Artan Borici

We suggest that the spectral properties near zero virtuality of three dimensional QCD, follow from a Hermitean random matrix model. The exact spectral density is derived for this family of random matrix models both for even and odd number…

High Energy Physics - Theory · Physics 2009-10-28 J. J. M. Verbaarschot , I. Zahed

Three aspects of symmetry structure of lattice chiral fermion in the overlap formalism are discussed. By the weak coupling expansion of the overlap Dirac operator, the axial anomaly associated to the chiral transformation proposed by…

High Energy Physics - Lattice · Physics 2009-10-31 Y. Kikukawa

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 launched a project to perform dymanical fermion simulations using the overlap fermion formulation for sea quarks. In order to avoid the appearace of near-zero modes of the hermitian Wilson-Dirac operator $H_W$, we introduce a pair of…

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

The Ginsparg-Wilson relation, if written in a suitable form, can be used as a condition for lattice Dirac operators of massless fermions also in odd dimensions. The fermion action with such a Dirac operator is invariant under a generalized…

High Energy Physics - Lattice · Physics 2010-02-03 W. Bietenholz , J. Nishimura

The thermodynamics of massless ideal gas of overlap quarks has been investigated both analytically and numerically for both zero and nonzero baryon chemical potential. Any \mu^2-divergence is shown analytically to be absent for a class of…

High Energy Physics - Lattice · Physics 2008-12-18 Debasish Banerjee , R. V. Gavai , Sayantan Sharma

The thermodynamics of massless ideal gas of overlap quarks has been investigated numerically for both zero and nonzero baryon chemical potential $\mu$. While the parameter M has been shown to be irrelevant in the continuum limit, it is…

High Energy Physics - Lattice · Physics 2008-11-26 R. V. Gavai , Sayantan Sharma

We introduce the Dirac eigenmode filtering of topological charge density associated with Ginsparg-Wilson fermions as a tool to investigate the local structure of topological charge fluctuations in QCD. The resulting framework is used to…

High Energy Physics - Lattice · Physics 2008-11-26 I. Horvath , S. J. Dong , T. Draper , F. X. Lee , K. F. Liu , J. B. Zhang , H. B. Thacker

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

High Energy Physics - Lattice · Physics 2015-06-25 Y. Kikukawa , T. Noguchi

Using non-perturbative techniques we have found the renormalisation factor, Z, in the RI-MOM scheme for quark bilinear operators in quenched QCD. We worked with overlap fermions using the Luescher-Weisz gauge action. Our calculation was…

High Energy Physics - Lattice · Physics 2016-09-01 M. Gürtler , R. Horsley , P. E. L. Rakow , C. J. Roberts , G. Schierholz , T. Streuer

The spectral and scattering theory for 1-dimensional Dirac operators with mass $m$ and with zero-range interactions are fully investigated. Explicit expressions for the wave operators and for the scattering operator are provided. These new…

Mathematical Physics · Physics 2015-06-18 K. Pankrashkin , S. Richard