178 research outputs found
Baxter Equation for the QCD Odderon
The Hamiltonian derived by Bartels, Kwiecinski and Praszalowicz for the study
of high-energy QCD in the generalized logarithmic approximation was found to
correspond to the Hamiltonian of an integrable spin chain. We study the
odderon Hamiltonian corresponding to three sites by means of the Bethe Ansatz
approach. We rewrite the Baxter equation, and consequently the Bethe Ansatz
equations, as a linear triangular system. We derive a new expression for the
eigenvectors and the eigenvalues, and discuss the quantization of the conserved
quantities.Comment: 14 pages, latex file, one figur
Effective action of magnetic monopole in three-dimensional electrodynamics with massless matter and gauge theories of superconductivity
We compute one-loop effective action of magnetic monopole in
three-dimensional electrodynamics of massless bosons and fermions and find that
it contains an infrared logarithm. So, when the number of massless matter
species is sufficiently large, monopoles are suppressed and in the weak
coupling limit charged particles are unconfined. This result provides some
support to gauge theories of high-temperature superconductors. It also provides
a mechanism by which interlayer tunneling of excitations with one unit of the
ordinary electric charge can be suppressed while that of a doubly charged
object is allowed.Comment: 8 pages, LATEX, UCLA/93/TEP/41 (the last sentence of the paragraph
concerning applications at the end of the paper has been deleted; mailing
problems have been corrected
Mean- Field Approximation and a Small Parameter in Turbulence Theory
Numerical and physical experiments on two-dimensional (2d) turbulence show
that the differences of transverse components of velocity field are well
described by a gaussian statistics and Kolmogorov scaling exponents. In this
case the dissipation fluctuations are irrelevant in the limit of small
viscosity. In general, one can assume existence of critical
space-dimensionality , at which the energy flux and all odd-order
moments of velocity difference change sign and the dissipation fluctuations
become dynamically unimportant. At the flow can be described by the
``mean-field theory'', leading to the observed gaussian statistics and
Kolmogorov scaling of transverse velocity differences. It is shown that in the
vicinity of the ratio of the relaxation and translation
characteristic times decreases to zero, thus giving rise to a small parameter
of the theory. The expressions for pressure and dissipation contributions to
the exact equation for the generating function of transverse velocity
differences are derived in the vicinity of . The resulting equation
describes experimental data on two-dimensional turbulence and demonstrate onset
of intermittency as and in three-dimensional flows in
close agreement with experimental data. In addition, some new exact relations
between correlation functions of velocity differences are derived. It is also
predicted that the single-point pdf of transverse velocity difference in
developing as well as in the large-scale stabilized two-dimensional turbulence
is a gaussian.Comment: 25 pages, 1 figur
Present status of the nonstrange and other flavor partners of the exotic Theta+ baryon
Given the existing empirical information about the exotic Theta+ baryon, we
analyze possible properties of its SU(3)F-partners, paying special attention to
the nonstrange member of the antidecuplet N*. The modified piN partial-wave
analysis presents two candidate masses, 1680 MeV and 1730 MeV. In both cases,
the N* should be rather narrow and highly inelastic. Our results suggest
several directions for experimental studies that may clarify properties of the
antidecuplet baryons, and structure of their mixing with other baryons. Recent
experimental evidence from the GRAAL and STAR Collaborations could be
interpreted as observations of a candidate for the Theta+ nonstrange partner.Comment: 4 pages, 1 figure, talk given at the Topical Group on Hadron Physics
(Fermilab, Oct. 24-26, 2004
Exact solution of the one-dimensional ballistic aggregation
An exact expression for the mass distribution of the ballistic
aggregation model in one dimension is derived in the long time regime. It is
shown that it obeys scaling with a scaling
function for and for
. Relevance of these results to Burgers turbulence is discussed.Comment: 11 pages, 2 Postscript figure
Stress-energy Tensor Correlators of a Quantum Field in Euclidean and spaces via the generalized zeta-function method
In this paper we calculate the vacuum expectation values of the stress-energy
bitensor of a massive quantum scalar field with general coupling to
N-dimensional Euclidean spaces and hyperbolic spaces which are Euclidean
sections of the anti-de Sitter (AdS) spaces. These correlators, also known as
the noise kernel, act as sources in the Einstein-Langevin equations of
stochastic gravity [1,2] which govern the induced metric fluctuations beyond
the mean-field dynamics described by the semiclassical Einstein equations of
semiclassical gravity. Because these spaces are maximally symmetric the
eigenmodes have analytic expressions which facilitate the computation of the
zeta-function [3,4]. Upon taking the second functional variation of the
generalized zeta function introduced in [5] we obtain the correlators of the
stress tensor for these two classes of spacetimes. Both the short and the large
geodesic distance limits of the correlators are presented for dimensions up to
11. We mention current research problems in early universe cosmology, black
hole physics and gravity-fluid duality where these results can be usefully
applied to.Comment: RevTeX, 35 pages, no figur
Baryogenesis, 30 Years after
A review of the basic principles of baryogenesis is given. Baryogenesis in
heavy particle decays as well as electroweak, SUSY-condensate, and spontaneous
baryogenesis are discussed. The models of abundant creation of antimatter in
the universe are briefly reviewed.Comment: 30 pages, latex twic
High Temperature Limit of the Confining Phase
The deconfining transition in non-Abelian gauge theory is known to occur by a
condensation of Wilson lines. By expanding around an appropriate Wilson line
background, it is possible at large to analytically continue the confining
phase to arbitrarily high temperatures, reaching a weak coupling confinement
regime. This is used to study the high temperature partition function of an
electric flux tube. It is found that the partition function corresponds
to that of a string theory with a number of world-sheet fields that diverges at
short distance.Comment: 13 page
Dynamical Anomalies and Intermittency in Burgers Turbulence
We analyze the field theory of fully developed Burgers turbulence. Its key
elements are shock fields, which characterize the singularity statistics of the
velocity field. The shock fields enter an operator product expansion describing
intermittency. The latter is found to be constrained by dynamical anomalies
expressing finite dissipation in the inviscid limit. The link between dynamical
anomalies and intermittency is argued to be important in a wider context of
turbulence.Comment: revised version, 4 pp., 1 fig., to appear in PR
Domain Walls in a FRW Universe
We solve the equations of motion for a scalar field with domain wall boundary
conditions in a Friedmann-Robertson-Walker (FRW) spacetime. We find (in
agreement with Basu and Vilenkin) that no domain wall solutions exist in de
Sitter spacetime for h = H/m >= 1/2, where H is the Hubble parameter and m is
the scalar mass. In the general FRW case we develop a systematic perturbative
expansion in h to arrive at an approximate solution to the field equations. We
calculate the energy momentum tensor of the domain wall configuration, and show
that the energy density can become negative at the core of the defect for some
values of the non-minimal coupling parameter xi. We develop a translationally
invariant theory for fluctuations of the wall, obtain the effective Lagrangian
for these fluctuations, and quantize them using the Bunch-Davies vacuum in the
de Sitter case. Unlike previous analyses, we find that the fluctuations act as
zero-mass (as opposed to tachyonic) modes. This allows us to calculate the
distortion and the normal-normal correlators for the surface. The normal-normal
correlator decreases logarithmically with the distance between points for large
times and distances, indicating that the interface becomes rougher than in
Minkowski spacetime.Comment: 23 pages, LaTeX, 7 figures using epsf.tex. Now auto-generates P
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