13,418 research outputs found
Semi-analytic calculation of the monopole order parameter in QCD
The monopole order parameter of QCD is computed in terms of gauge invariant
field strength correlators. Both quantities are partially known from numerical
simulations on the lattice. A new insight results on the structure of the
confining vacuum.Comment: Talk presented at QCD06, Montpellier 3-7 July 2006. To appear in the
proceeding
Gauge-invariant nonlocal quark condensates in QCD
We study, by numerical simulations on a lattice, the behaviour of the
gauge-invariant nonlocal quark condensates in the QCD vacuum both in the
quenched approximation and with four flavours of dynamical staggered fermions.
The correlation length of the condensate is determined to be roughly twice as
big as in the case of the gluon field strength correlators.Comment: LATTICE98(confine
't Hooft tensor for generic gauge group
We study monopoles in gauge theories with generic gauge group. Magnetic
charges are in one-to-one correspondence with the second homotopy classes at
spatial infinity (), which are therefore identified by the 't Hooft
tensor. We determine the 't Hooft tensor in the general case. These issues are
relevant to the understanding of Color Confinement.Comment: 5 pages. Contribution to the Conference QCD08, Montpellier 7-12 July
2008 To appear in the proceeding
Condensation of vortices and disorder parameter in 3d Heisenberg model
The 3d Heisenberg model is studied from a dual point of view. It is shown
that the disordered phase corresponds to condensation of vortices in the
vacuum, and the critical indices are computed from the corresponding disorder
parameter.Comment: LATTICE98(spin
Dual superconducting properties of the QCD vacuum
A consistent description of the confining QCD vacuum as a dual superconductor
requires a determination of fundamental parameters such as the superconductor
correlation length and the field penetration depth , which
determine whether the superconductor is of type I or type II. We illustrate
preliminary results of a lattice determination of for the case of pure
Yang-Mills with two colors, obtained by measuring the temporal correlator of a
disorder parameter detecting dual superconductivity.Comment: 4 pages, 2 figures, talk presented at QCD05 (Montpellier) 4-9 July
200
Field strength correlators in QCD at zero and non-zero temperature
We study, by numerical simulations on a lattice, the behaviour of the
gauge--invariant field strength correlators in QCD both at zero temperature,
down to a distance of 0.1 fm, and at finite temperature, across the
deconfinement phase transition.Comment: Talk given at the ``High Energy Conference on Quantum
Chromodynamics'', Montpellier (France), 4-12 July 1996 (QCD 96); 5 pages,
LaTeX file, uses ``espcrc2.sty''+ 5 PS figure
What is the order of the deconfining phase transition?
The techniques are discussed by which the order of the deconfining phase
transition is investigated on the lattice. QCD with is a special case,
which can provide information on the mechanism of confinement.Comment: Talk at QCD 2003, Montpellier, July 2003, to appear in the
proceedings. 4 pages, 1 figur
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