English
Related papers

Related papers: Vacuum structure as seen by overlap fermions

200 papers

The spectral properties of the Wilson-Dirac operator in 2-dimensional QED responsible for the appearance of exceptional configurations in quenched simulations are studied in detail. The mass singularity structure of the quenched functional…

High Energy Physics - Lattice · Physics 2009-10-30 W. Bardeen , A. Duncan , E. Eichten , H. Thacker

We discuss a simple formula which connects the field-strength tensor to a spectral sum over certain quadratic forms of the eigenvectors of the lattice Dirac operator. We analyze these terms for the near zero-modes and find that they give…

High Energy Physics - Lattice · Physics 2009-11-07 Christof Gattringer

We study physics at temperatures just above the QCD phase transition (Tc) using chiral (overlap) Fermions in the quenched approximation of lattice QCD. Exact zero modes of the overlap Dirac operator are localized and their frequency of…

High Energy Physics - Lattice · Physics 2011-07-19 Rajiv V. Gavai , Sourendu Gupta , R. Lacaze

We report on new analyses of the topological and chiral vacuum structure of four-dimensional QCD on the lattice. Correlation functions as well as visualization of monopole currents in the maximally Abelian gauge emphasize their topological…

High Energy Physics - Lattice · Physics 2008-11-26 E. -M. Ilgenfritz , H. Markum , M. Müller--Preussker , W. Sakuler , S. Thurner

We examine how dynamical fermions affect both the UV and infrared structure of the QCD vacuum. We consider large $28^3 \times 96$ lattices from the MILC collaboration, using a gluonic definition of the topological charge density, founded on…

High Energy Physics - Lattice · Physics 2009-01-09 Peter J. Moran , Derek B. Leinweber

Lattice topological charge associated with Ginsparg-Wilson fermions exhibits generic topological stability over quantum ensemble of configurations contributing to the QCD path integral. Moreover, the underlying chiral symmetry leads to the…

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

We study topological aspects of the QCD vacuum structure in SU(2) lattice gauge theory with the abelian gauge fixing. The index of the Dirac operator is measured by using the Wilson fermion in the quenched approximation. We find…

High Energy Physics - Lattice · Physics 2009-10-30 Shoichi Sasaki , Osamu Miyamura

We analyze the topological and fermionic vacuum structure of four-dimensional QCD on the lattice by means of correlators of fermionic observables and topological densities. We show the existence of strong local correlations between the…

High Energy Physics - Lattice · Physics 2009-10-31 W. Sakuler , S. Thurner , H. Markum

We present some results pertaining to partially quenched formulations of the overlap/domain wall operator with the Thirring model in 2+1D. Auxiliary fields are generated with a Shamir domain wall approach and measurements of eigenvalues and…

High Energy Physics - Lattice · Physics 2021-12-07 Jude Worthy , Simon Hands

The short-range structure of the 2+1 flavour QCD vacuum is studied through visualisations of the topological charge density. Of particular interest is a new Gaussian weighted smearing algorithm which is applied to the rough topological…

High Energy Physics - Lattice · Physics 2008-05-29 P. J. Moran , D. B. Leinweber

Long-range order of a specific kind has recently been found directly in configurations dominating the regularized QCD path integral. In particular, a low-dimensional global structure was identified in typical space-time distributions of…

High Energy Physics - Lattice · Physics 2009-11-11 A. Alexandru , I. Horvath , J. B. Zhang

A disorder parameter detecting dual superconductivity of the vacuum is measured across the chiral phase transition in full QCD with two flavours of dynamical staggered fermions. The observed behaviour is similar to the quenched case.

High Energy Physics - Lattice · Physics 2008-11-26 J. M. Carmona , M. D'Elia , L. Del Debbio , A. Di Giacomo , B. Lucini , G. Paffuti

Using a reweighting technique combined with a low-mode truncation of the fermionic determinant, we estimate the quark-mass dependence of the QCD topological susceptibility with overlap fermions. In contrast to previous lattice simulations…

High Energy Physics - Lattice · Physics 2009-09-25 Tamas G. Kovacs

We consider here the vacuum structure in QCD with both quark and gluon condensates and a variational ansatz for the ground state. The method is nonperturbative using only equal time algebra for the field operators. We then find that a…

High Energy Physics - Phenomenology · Physics 2015-06-25 A. Mishra , H. Mishra , Varun Sheel , S. P. Misra , P. K. Panda

The vacuum structure of N = 2 linear supersymmetry (LSUSY) invariant QED, which is equivalent to N = 2 nonlinear supersymmetry (NLSUSY) model, is studied explicitly in two dimensional space-time (d = 2). Two different isometries SO(1,3) and…

High Energy Physics - Theory · Physics 2009-06-19 K. Shima , M. Tsuda , W. Lang

We measure the low lying eigenmodes of an overlap Dirac operator on 2--flavor staggered configurations. By comparing the eigenmode distribution to the predictions of Random Matrix Theory we test to what accuracy staggered configurations…

High Energy Physics - Lattice · Physics 2008-11-26 Anna Hasenfratz , Roland Hoffmann

We discuss here a model of QCD vacuum in terms of quark antiquark and gluon condensates alongwith their fluctuations. The correlation functions of hadronic currents in such a vacuum are evaluated to extract hadron properties. The presence…

Nuclear Theory · Physics 2007-05-23 Hiranmaya Mishra

Action and topological charge densities of the Euclidean-space QCD vacuum are visualized in three-dimensional slices of a 24^3 x 36 space-time lattice and an order-a^2 improved 16^3 x 32 lattice. Features include instanton anti-instanton…

High Energy Physics - Lattice · Physics 2007-05-23 Derek B. Leinweber

An attempt is made to describe from first principles the large-scale structure of the confining vacuum in quantum chromodynamics. Starting from our previous variational studies of the SU(2) pure gauge theory in an external Abelian…

High Energy Physics - Phenomenology · Physics 2024-02-27 Paolo Cea

We study the spatial correlator of the topological charge density operator in pure SU(3) gauge theory and in two flavor QCD. We show that the data for distances up to about 1 fm is consistent with a vacuum consisting of individual…

High Energy Physics - Lattice · Physics 2009-10-31 Anna Hasenfratz