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Related papers: Techniques for using the overlap-Dirac operator to…

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Progress in extracting excited-state baryon masses in lattice QCD using large sets of spatially-extended operators is presented. The use of stochastic estimates of all-to-all quark propagators with variance reduction techniques is…

High Energy Physics - Lattice · Physics 2019-08-13 Colin Morningstar

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

Random matrix theory and chiral Lagrangians offer a convenient tool for the exact calculation of microscopic spectral correlators of the Dirac operator in a well-defined finite-volume scaling regime.

High Energy Physics - Lattice · Physics 2009-10-31 P. H. Damgaard

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

We formulate the massive overlap fermions on anisotropic lattices. We find that the dispersion relation for the overlap fermion resembles the continuum form in the low-momentum region once the bare parameters are properly tuned. The quark…

High Energy Physics - Lattice · Physics 2010-10-27 Xin Li , Guozhan Meng , Xu Feng , Chuan Liu

We study the global symmetries of naive lattices Dirac operators in QCD-like theories in any dimension larger than two. In particular we investigate how the chosen number of lattice sites in each direction affects the global symmetries of…

High Energy Physics - Lattice · Physics 2017-08-09 Mario Kieburg , Tim R. Würfel

In the epsilon-regime of QCD the main features of the spectrum of the low-lying eigenvalues of the (euclidean) Dirac operator are expected to be described by a certain universality class of random matrix models. In particular, the latter…

High Energy Physics - Lattice · Physics 2009-11-10 Leonardo Giusti , Martin Lüscher , Peter Weisz , Hartmut Wittig

We argue that lattice simulations of full QCD with varying quark mass are best conducted at fixed lattice spacing rather than at fixed $\beta$. We present techniques which enable this to be carried out effectively, namely the tuning in bare…

High Energy Physics - Lattice · Physics 2009-10-31 Alan C. Irving , UKQCD Collaboration

Determining the QCD phase diagram is a pressing task in view of its relevance for nuclear and astro-particle physics programmes. We review the current status of lattice calculations of the phase diagram in the (T,\mu_B)-plane for baryon…

High Energy Physics - Phenomenology · Physics 2009-01-14 Owe Philipsen

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 numerically evaluate the one-loop counterterms for the four-dimensional Wess-Zumino model formulated on the lattice using Ginsparg-Wilson fermions of the overlap (Neuberger) variety, together with an auxiliary fermion (plus…

High Energy Physics - Lattice · Physics 2014-11-21 Chen Chen , Eric Dzienkowski , Joel Giedt

New exact upper and lower bounds are derived on the spectrum of the square of the hermitian Wilson Dirac operator. It is hoped that the derivations and the results will be of help in the search for ways to reduce the cost of simulations…

High Energy Physics - Lattice · Physics 2009-07-09 H. Neuberger

The lattice QCD simulation with the lattice chiral symmetry is very attractive, however, it is difficult to maintain the symmetry at a modest numerical computation cost. A candidate to reduce the computational cost during the configuration…

High Energy Physics - Lattice · Physics 2013-10-31 Ken-Ichi Ishikawa

Lattice fermions with suppressed high momentum modes solve the ultraviolet slowing down problem in lattice QCD. This paper describes a stochastic evaluation of the effective action of such fermions. The method is a based on the Lanczos…

High Energy Physics - Lattice · Physics 2008-11-26 Artan Borici

We discuss properties of Quantum Chromodynamics at finite temperature obtained by means of lattice simulations with overlap fermions. This fermion discretization preserves chiral symmetry even at finite lattice spacing. We present details…

High Energy Physics - Lattice · Physics 2024-01-08 Z. Fodor , A. Yu. Kotov , K. Szabo

We describe and test a method to compute Euclidean meson two-point functions in lattice QCD. The contribution from the low-lying eigenmodes of the Dirac operator is averaged over all positions of the quark sources. The contribution from the…

High Energy Physics - Lattice · Physics 2009-11-10 Thomas DeGrand , Stefan Schaefer

The Rational Hybrid Monte Carlo (RHMC) algorithm extends the Hybrid Monte Carlo algorithm for lattice QCD simulations to situations involving fractional powers of the determinant of the quadratic Dirac operator. This avoids the updating…

High Energy Physics - Lattice · Physics 2008-11-26 J. B. Kogut , D. K. Sinclair

We discuss the spectrum of the QCD Dirac operator both at zero and at nonzero baryon chemical potential. We show that, in the ergodic domain of QCD, the Dirac spectrum can be obtained from the replica limit of a Toda lattice equation. At…

High Energy Physics - Theory · Physics 2017-08-23 K. Splittorff , J. J. M. Verbaarschot

Lattice QCD calculations using gauge smearing for fermion kernels are computationally efficient. Hypercubic blocking (nHYP smearing) has been shown to reduce scaling errors. In this work we use an improved action for $N_f=2$ QCD, based on…

High Energy Physics - Lattice · Physics 2020-11-18 Hossein Niyazi , Andrei Alexandru , Frank X. Lee , Ruairí Brett

We discuss the lattice formulation of gauge theories with fermions in arbitrary representations of the color group, and present in detail the implementation of the HMC/RHMC algorithm for simulating dynamical fermions. We discuss the…

High Energy Physics - Lattice · Physics 2014-11-18 Luigi Del Debbio , Agostino Patella , Claudio Pica