595 research outputs found

    Evidence of Strong Correlation between Instanton and QCD-monopole on SU(2) Lattice

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    The correlation between instantons and QCD-monopoles is studied both in the lattice gauge theory and in the continuum theory. An analytical study in the Polyakov-like gauge, where A4(x)A_4(x) is diagonalized, shows that the QCD-monopole trajectory penetrates the center of each instanton, and becomes complicated in the multi-instanton system. Using the SU(2) lattice with 16416^4, the instanton number is measured in the singular (monopole-dominating) and regular (photon-dominating) parts, respectively. The monopole dominance for the topological charge is found both in the maximally abelian gauge and in the Polyakov gauge.Comment: 4 pages, Latex, 3 figures. Talk presented by H. Suganuma at International Symposium on 'Lattice Field Theory', July 11 - 15, 1995, Melbourne, Australi

    Confinement Properties in the Multi-Instanton System

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    We investigate the confinement properties in the multi-instanton system, where the size distribution is assumed to be ρ5 \rho^{-5} for the large instanton size ρ \rho . We find that the instanton vacuum gives the area law behavior of the Wilson loop, which indicates existence of the linear confining potential. In the multi-instanton system, the string tension increases monotonously with the instanton density, and takes the standard value σ1GeV/fm \sigma \simeq 1 GeV/fm for the density (N/V)1/4=200MeV (N/V)^{{1/4}} = 200 MeV . Thus, instantons directly relate to color confinement properties.Comment: Talk presented by M. Fukushima at ``Lattice '97'', the International Symposium on Lattice Field Theory, 22 - 26 July 1997, in Edinburgh, Scotland, 3 pages, Plain Late

    Monopole Current Dynamics and Color Confinement

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    Color confinement can be understood by the dual Higgs theory, where monopole condensation leads to the exclusion of the electric flux from the QCD vacuum. We study the role of the monopole for color confinement by investigating the monopole current system. When the self-energy of the monopole current is small enough, long and complicated monopole world-lines appear, which is a signal of monopole condensation. In the dense monopole system, the Wilson loop obeys the area-law, and the string tension and the monopole density have similar behavior as the function of the self-energy, which seems that monopole condensation leads to color confinement. On the long-distance physics, the monopole current system almost reproduces essential features of confinement properties in lattice QCD. In the short-distance physics, however, the monopole-current theory would become nonlocal and complicated due to the monopole size effect. This monopole size would provide a critical scale of QCD in terms of the dual Higgs mechanism.Comment: 6 pages LaTeX, 5 figures, uses espcrc1.sty, Talk presented at International Conference on Quark Lepton Nuclear Physics, Osaka, May. 199

    Confinement and Topological Charge in the Abelian Gauge of QCD

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    We study the relation between instantons and monopoles in the abelian gauge. First, we investigate the monopole in the multi-instanton solution in the continuum Yang-Mills theory using the Polyakov gauge. At a large instanton density, the monopole trajectory becomes highly complicated, which can be regarded as a signal of monopole condensation. Second, we study instantons and monopoles in the SU(2) lattice gauge theory both in the maximally abelian (MA) gauge and in the Polyakov gauge. Using the 163×416^3 \times 4 lattice, we find monopole dominance for instantons in the confinement phase even at finite temperatures. A linear-type correlation is found between the total monopole-loop length and the integral of the absolute value of the topological density (the total number of instantons and anti-instantons) in the MA gauge. We conjecture that instantons enhance the monopole-loop length and promote monopole condensation.Comment: 3 pages, LaTeX, Talk presented at LATTICE96(topology

    Distribution of fermionic and topological observables on the lattice

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    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 topological charge and monopole density on the one side and the quark condensate, charge and chiral density on the other side. Visualization of individual gauge configurations demonstrates that instantons (antiinstantons) carry positive (negative) chirality, whereas the quark charge density fluctuates in sign within instantons.Comment: 10 pages, 5 eps figures, to appear in Phys. Lett.

    The Role of Monopoles for Color Confinement

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    We study the role of the monopole for color confinement by using the monopole current system. For the self-energy of the monopole current less than ln(2d1)(2d-1), long and complicated monopole world-lines appear and the Wilson loop obeys the area law, and therefore the monopole current system almost reproduces essential features of confinement properties in the long-distance physics. In the short-distance physics, however, the monopole-current theory would become nonlocal due to the monopole size effect. This monopole size would provide a critical scale of QCD in terms of the dual Higgs mechanism.Comment: 3 pages LaTeX, 3 figures, uses espcrc2.sty, Talk presented at lattice97, Edinburgh, Scotland, July. 199

    Temporal meson correlators at finite temperature on quenched anisotropic lattice

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    We study charmonium correlators at finite temperature in quenched anisotropic lattice QCD. The smearing technique is applied to enhance the low energy part of the correlator. We use two analysis procedures: the maximum entropy method for extraction of the spectral function without assuming specific form, as an estimate of the shape of spectral function, and the χ2\chi^2 fit assuming typical forms as quantitative evaluation of the parameters associated to the forms. We find that at T0.9TcT\simeq 0.9T_c the ground state peak has almost the same mass as at T=0 and almost vanishing width. At T1.1TcT\simeq 1.1T_c, our result suggests that the correlator still has nontrivial peak structure at almost the same position as below TcT_c with finite width.Comment: Lattice 2002 Nonzero temperature 3page
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