718 research outputs found
The Width of the Colour Flux Tube
We discuss and rederive in a general way the logarithmic growth of the mean
squared width of the colour flux tube as a function of the interquark
separation. Recent data on 3D gauge theory, combined with high precision
data on the interface physics of the 3D Ising model fit nicely this behaviour
over a range of more than two orders of magnitude.Comment: 3 pages, contribution to the Lattice '94 conference, uuencoded
compressed ps-fil
Thermal operators and cluster topology in q-state Potts Model
We discuss a new class of identities between correlation functions which
arise from a local Z_2 invariance of the partition function of the q-state
Potts model on general graphs or lattices. Their common feature is to relate
the thermal operators of the Potts model to some topological properties of the
Fortuin-Kasteleyn clusters. In particular it turns out that any even
correlation function can be expressed in terms of observables which probe the
linking properties of these clusters. This generalises a class of analogous
relations recently found in the Ising model.Comment: 6 pages, latex, enlarged version, accepted for publication in Journal
of Physics
Random percolation as a gauge theory
Three-dimensional bond or site percolation theory on a lattice can be
interpreted as a gauge theory in which the Wilson loops are viewed as counters
of topological linking with random clusters. Beyond the percolation threshold
large Wilson loops decay with an area law and show the universal shape effects
due to flux tube quantum fluctuations like in ordinary confining gauge
theories. Wilson loop correlators define a non-trivial spectrum of physical
states of increasing mass and spin, like the glueballs of ordinary gauge
theory. The crumbling of the percolating cluster when the length of one
periodic direction decreases below a critical threshold accounts for the finite
temperature deconfinement, which belongs to 2-D percolation universality class.Comment: 20 pages, 14 figure
On the relation between the width of the flux tube and in lattice gauge theories
Within the framework of a quantum flux tube model for the interquark
potential it is possible to predict that in (2+1) dimensions the space-like
string tension must increase with the temperature in the deconfined phase and
that the thickness of the flux tube must coincide with the inverse of the
deconfinement temperature. Both these predictions are in good agreement with
some recent numerical simulations of SU(2) and gauge models.Comment: 3 pages, uuencoded .ps file (Proceeding of Lattice '93 Conference
The Stefan-Boltzmann law in a small box and the pressure deficit in hot SU(N) lattice gauge theory
The blackbody radiation in a box L^3 with periodic boundary conditions in
thermal equilibrium at a temperature T is affected by finite-size effects.
These bring about modifications of the thermodynamic functions which can be
expressed in a closed form in terms of the dimensionless parameter LT. For
instance, when LT~4 - corresponding to the value where the most reliable SU(N)
gauge lattice simulations have been performed above the deconfining temperature
T_c - the deviation of the free energy density from its thermodynamic limit is
about 5%. This may account for almost half of the pressure deficit observed in
lattice simulations at T~ 4 T_c.Comment: 9 pages, 2 figures v2:a side remark on the final result and
references adde
Monopole clusters, center vortices, and confinement in a Z(2) gauge-Higgs system
We propose to use the different kinds of vacua of the gauge theories coupled
to matter as a laboratory to test confinement ideas of pure Yang-Mills
theories. In particular, the very poor overlap of the Wilson loop with the
broken string states supports the 't Hooft and Mandelstam confinement criteria.
However in the Z(2) gauge-Higgs model we use as a guide we find that the
condensation of monopoles and center vortices is a necessary, but not
sufficient condition for confinement.Comment: 13 pages, 6 figures, minor changes, version to be published on Phys.
Rev.
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