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Related papers: Low-Dimensional Long-Range Topological Charge Stru…

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The topological structure of the QCD vacuum can be probed by monitoring the spatial localization of the low-lying Dirac eigenmodes. This approach can be pursued on the lattice, and unlike the traditional one requires no smoothing of the…

High Energy Physics - Lattice · Physics 2008-11-26 Philippe de Forcrand

We discuss the utility of low-lying Dirac eigenmodes for studying the nature of topological charge fluctuations in QCD. The implications of previous results using the local chirality histogram method are discussed, and the new results using…

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

We perform an analysis of the topological and chiral vacuum structure of four-dimensional QCD on the lattice at finite temperature. From correlation functions we show the existence of local correlations between the topological charge…

High Energy Physics - Lattice · Physics 2009-10-30 Markus Feurstein , Harald Markum , Stefan Thurner

The low-lying eigenmodes of the Dirac operator associated with typical gauge field configurations in QCD encode, among other low-energy properties, the physics behind the solution to the $U_A(1)$ problem (i.e. the origin of the $\eta'$…

High Energy Physics - Lattice · Physics 2014-11-17 Ivan Horvath , Nathan Isgur , John McCune , H. B. Thacker

We investigate SU(2) gauge fields topology using new approach, which exploits the well known connection between SU(2) gauge theory and quaternionic projective sigma-models and allows to formulate the topological charge density entirely in…

High Energy Physics - Lattice · Physics 2009-11-11 F. V. Gubarev , S. M. Morozov

This talk is a review of our studies of instantons and their properties as seen in our lattice simulations of SU(2) gauge theory. We have measured the topological susceptibility and the size distribution of instantons in the QCD vacuum. We…

High Energy Physics - Lattice · Physics 2016-09-01 T. DeGrand , Anna Hasenfratz , Tamas Kovacs

We update our numerical investigation of topological structures around static quarks in pure gauge QCD by results of the first runs including dynamical quarks. Simulations were performed on an $8^3\times4$ lattice, with $SU(3)$ Wilson…

High Energy Physics - Lattice · Physics 2008-11-26 M. Faber , H. Markum , S. Olejnik , W. Sakuler

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 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 investigate how the topological charge density in lattice QCD simulations is affected by violations of chiral symmetry in different fermion actions. 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 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

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

We calculate the lattice two-point function of topological charge density in pure-glue QCD using the discretization of the operator based on the overlap Dirac matrix. Utilizing data at three lattice spacings it is shown that the continuum…

High Energy Physics - Lattice · Physics 2008-11-26 I. Horvath , A. Alexandru , J. B. Zhang , Y. Chen , S. J. Dong , T. Draper , K. F. Liu , N. Mathur , S. Tamhankar , H. B. Thacker

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

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

A detailed comparison is made between the topological structure of quenched QCD as revealed by the recently proposed over-improved stout-link smearing in conjunction with an improved gluonic definition of the topological density on one hand…

High Energy Physics - Lattice · Physics 2014-11-18 E. -M. Ilgenfritz , D. Leinweber , P. Moran , K. Koller , G. Schierholz , V. Weinberg

The structure of the SU(3) gauge-field vacuum is explored through visualisations of centre vortices and topological charge density. Stereoscopic visualisations highlight interesting features of the vortex vacuum, especially the frequency…

High Energy Physics - Lattice · Physics 2021-02-03 James C. Biddle , Waseem Kamleh , Derek B. Leinweber

We present a study of the topological susceptibility in lattice QCD with two degenerate flavors of dynamical quarks. The topological charge is measured on gauge configurations generated with a renormalization group improved gauge action and…

Overlap fermions, which preserve exact chiral symmetry on the lattice, provide a powerful tool for investigating the topological structure of the vacuum. Applying this formulation to zero-temperature quenched SU(3) configurations generated…

High Energy Physics - Lattice · Physics 2007-05-23 Y. Koma , E. -M. Ilgenfritz , K. Koller , G. Schierholz , T. Streuer , V. Weinberg

Both theoretical arguments and Monte Carlo observations indicate that the topological structure of the QCD vacuum consists of a laminated array of extended, coherent codimension-one membranes of alternating sign. Large-$N_c$ arguments,…

High Energy Physics - Theory · Physics 2013-02-05 H. B. Thacker