905 research outputs found
Dimensional reduction and a Z(3) symmetric model
We present first results from a numerical investigation of a Z(3) symmetric
model based on dimensional reduction.Comment: Talk presented at XXI International Symposium on Lattice Field Theory
lattice2003(Non-zero temperature and density
Intermittency in a single event
The possibility to study intermittency in a single event of high multiplicity
is investigated in the framework of the model. It is found that, for
cascade long enough, the dispersion of intermittency exponents obtained from
individual events is fairly small. This fact opens the possibility to study the
distribution of the intermittency parameters characterizing the cascades seen
(by observing intermittency) in particle spectra.Comment: 7 pages, latex, 2 figures available on request by e-mai
Screening Masses in Dimensionally Reduced (2+1)D Gauge Theory
We discuss the screening masses and residue factorisation of the SU(3) (2+1)D
theory in the dimensional reduction formalism. The phase structure of the
reduced model is also investigated.Comment: 3 pages, Lattice 2001(gaugetheories
Dimensional reduction in QCD: Lessons from lower dimensions
In this contribution we present the results of a series of investigations of
dimensional reduction, applied to SU(3) gauge theory in 2 + 1 dimensions. We
review earlier results, present a new reduced model with Z(3) symmetry, and
discuss the results of numerical simulations of this model.Comment: 10 pages, Talk given at Workshop on Finite Density QCD, Nara Japan
10-12 Jul 200
Causal and homogeneous networks
Growing networks have a causal structure. We show that the causality strongly
influences the scaling and geometrical properties of the network. In particular
the average distance between nodes is smaller for causal networks than for
corresponding homogeneous networks. We explain the origin of this effect and
illustrate it using as an example a solvable model of random trees. We also
discuss the issue of stability of the scale-free node degree distribution. We
show that a surplus of links may lead to the emergence of a singular node with
the degree proportional to the total number of links. This effect is closely
related to the backgammon condensation known from the balls-in-boxes model.Comment: short review submitted to AIP proceedings, CNET2004 conference;
changes in the discussion of the distance distribution for growing trees,
Fig. 6-right change
Nuclear attenuation of high energy multi-hadron systems in the string model
Nuclear attenuation of the multi-hadron systems in the string model is
considered. The improved two-scale model with set of parameters obtained
recently for the single hadron attenuation is used for calculation of the
multiplicity ratios of the one-, two- and three-hadron systems electroproduced
on nuclear and deuterium targets. The comparison of the features of the one-,
two- and three-hadron systems is performed. The predictions of the model for
multiplicity ratios of multi-hadron systems as functions of different
convenient variables are presented.Comment: 7 pages, 6 figure
Condensation in nongeneric trees
We study nongeneric planar trees and prove the existence of a Gibbs measure
on infinite trees obtained as a weak limit of the finite volume measures. It is
shown that in the infinite volume limit there arises exactly one vertex of
infinite degree and the rest of the tree is distributed like a subcritical
Galton-Watson tree with mean offspring probability . We calculate the rate
of divergence of the degree of the highest order vertex of finite trees in the
thermodynamic limit and show it goes like where is the size of the
tree. These trees have infinite spectral dimension with probability one but the
spectral dimension calculated from the ensemble average of the generating
function for return probabilities is given by if the weight
of a vertex of degree is asymptotic to .Comment: 57 pages, 14 figures. Minor change
Three dimensional finite temperature SU(3) gauge theory in the confined region and the string picture
We determine the correlation between Polyakov loops in three dimensional
SU(3) gauge theory in the confined region at finite temperature. For this
purpose we perform lattice calculations for the number of steps in the
temperature direction equal to six. This is expected to be in the scaling
region of the lattice theory. We compare the results to the bosonic string
model. The agreement is very good for temperatures T<0.7T_c, where T_c is the
critical temperature. In the region 0.7T_c<T<T_c we enter the critical region,
where the critical properties of the correlations are fixed by universality to
be those of the two dimensional three state Potts model. Nevertheless, by
calculating the critical lattice coupling, we show that the ratio of the
critical temperature to the square root of the zero temperature string tension,
where the latter is taken from the literature, remains very near to the string
model prediction.Comment: 11 pages, 1 figure, 1 tabl
Phase Structure of Dynamical Triangulation Models in Three Dimensions
The dynamical triangulation model of three-dimensional quantum gravity is
shown to have a line of transitions in an expanded phase diagram which includes
a coupling mu to the order of the vertices. Monte Carlo renormalization group
and finite size scaling techniques are used to locate and characterize this
line. Our results indicate that for mu < mu1 ~ -1.0 the model is always in a
crumpled phase independent of the value of the curvature coupling. For mu < 0
the results are in agreement with an approximate mean field treatment. We find
evidence that this line corresponds to first order transitions extending to
positive mu. However, the behavior appears to change for mu > mu2 ~ 2-4. The
simplest scenario that is consistent with the data is the existence of a
critical end point
Z(3) Symmetric Dimensional Reduction of (2+1)D QCD
Here we present a candidate for a Z(3)-symmetric reduced action for the
description of the (2+1)D SU(3) gauge theoryComment: 2 pages, Statistical QCD pro
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