184 research outputs found
Upper bound on the cutoff in lattice Electroweak theory
We investigate numerically lattice Weinberg - Salam model without fermions
for realistic values of the fine structure constant and the Weinberg angle. We
also analyze the data of the previous numerical investigations of lattice
Electroweak theory. We have found that moving along the line of constant
physics when the lattice spacing is decreased, one should leave the
physical Higgs phase of the theory at a certain value of . Our estimate of
the minimal value of the lattice spacing is .Comment: Latex, 21 pages, 3 figures, to appear in JHE
Central Dominance and the Confinement Mechanism in Gluodynamics
New topological objects, which we call center monopoles, naturally arise in
the Maximal Center Projection of SU(3) gluodynamics. The condensate of the
center monopoles is the order parameter of the theory.Comment: 4 pages revtex, 3 figure
A hidden symmetry in the Standard Model
We found an additional symmetry hidden in the fermion and Higgs sectors of
the Standard Model. It is connected to the centers of the SU(3) and SU(2)
subgroups of the gauge group. A lattice regularization of the whole Standard
Model is constructed that possesses this symmetry.Comment: 6 pages, no figures. Shortened versio
Abelian Monopoles and Action Density in SU(2) Gluodynamics on the Lattice
We show that the extended Abelian magnetic monopoles in the Maximal Abelian
projection of lattice SU(2) gluodynamics are locally correlated with the
magnetic and the electric parts of the SU(2) action density. These correlations
are observed in the confined and in the deconfined phases.Comment: 11 pages, LaTeX2e, 5 figures, uses epsf.sty; revision: Introduction
is extended and a few references are adde
Standard Model with the additional symmetry on the lattice
An additional symmetry hidden in the fermion and Higgs sectors of the
Standard Model has been found recently\cite{BVZ2003}. A lattice regularization
of the Standard Model was constructed that possesses this symmetry. In
\cite{BVZ2004} we have reported our results on the numerical simulation of the
Electroweak sector of the model. In this paper we report our results on the
numerical simulation of the full () model. The
phase diagram of the model has been investigated using static quark and lepton
potentials. Various types of monopoles have been constructed. Their densities
appear to be sensitive to the phase transition lines. Differences between the
realizations of the Standard Model which do or do not possess the mentioned
symmetry, are discussed.Comment: Latex, 14 page
symmetry, electroweak transition, and magnetic monopoles at high temperature
We consider the lattice realization of the Standard Model with an additional
symmetry. Numerical simulations were performed on the asymmetric lattice,
which corresponds to the finite temperature theory. Our choice of parameters
corresponds to large Higgs masses ( Gev). The phase diagram was
investigated and has been found to be different from that of the usual lattice
realization of the Standard Model. It has been found, that the
confinement-deconfinement phase transition lines for the SU(2) and SU(3) fields
coincide. The transition line between Higgs and symmetric deconfinement parts
of the phase diagram and the confinement-deconfinement transition line meet in
a triple point. The transition between Higgs and symmetric parts of the phase
diagram corresponds to the finite temperature electroweak transition/crossover.
We see for the first time evidence that Nambu monopoles are condensed at
while at their condensate vanishes.Comment: Latex, 14 page
Evidence for the reality of singular configurations in SU(2) gauge theory
We consider the SU(2) lattice gauge model and investigate numerically the
continuum limit of the simple center vortices which are singular configurations
of the gauge fields. We found that the vortices remain alive in the continuum
theory. Also we investigate the Creutz ratio and found that for all it
vanishes for those field configurations which do not contain the simple center
vortices inside the considered Wilson loop. It leads us to the conclusion that
these singular field configurations play a real role in the continuum theory.Comment: 10 pages LaTeX, 2 .eps figure
The Simple Center Projection of SU(2) Gauge Theory
We consider the SU(2) lattice gauge model. We propose a new gauge invariant
definition of center projection, which we call the Simple Center Projection. We
demonstrate the center dominance, i.e., the coincidence of the projected
potential with the full potential up to the mass renormalization term at low
energies. We also consider the center vortices and the center monopoles ({\em
nexuses}). It turns out that the behavior of such objects qualitatively
coincides with the behavior of the vortices and monopoles in the Maximal Center
gauge. The connection of the condensation of nexuses with the dual
superconductor theory is discussed. Numerically the procedure of extracting the
center vortices proposed in this paper is much simpler than the usual Maximal
Center Projection.Comment: 11 pages LaTeX, four figure
Short Range Linear Potential in 3D Lattice Compact QED
We study the static potential between electric charges in the finite
temperature three dimensional compact gauge theory on the lattice. We show that
in the deconfinement phase at small separations between the charges the
potential contains a linearly rising piece which goes over into the Coulomb
potential as the distance between the charges is increased. The linear
potential is due to the gas of magnetic dipoles which are realized as
monopole-antimonopole bound states.Comment: 10 pages, 6 EPS figures, LaTeX2e, uses epsfig.st
10 D Euclidean quantum gravity on the lattice
10 D Euclidean quantum gravity is investigated numerically using the
dynamical triangulation approach. It has been found that the behavior of the
model is similar to that of the lower dimensional models. However, it turns out
that there are a few features that are not present in the lower dimensional
models.Comment: 3 pages, talk presented at Lattice200
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