767 research outputs found
One gluon, two gluon: multigluon production via high energy evolution
We develop an approach for calculating the inclusive multigluon production
within the JIMWLK high energy evolution. We give a formal expression of
multigluon cross section in terms of a generating functional for arbitrary
number of gluons . In the dipole limit the expression simplifies
dramatically. We recover the previously known results for single and double
gluon inclusive cross section and generalize those for arbitrary multigluon
amplitude in terms of Feynman diagramms of Pomeron - like objects coupled to
external rapidity dependent field . We confirm the conclusion that the
AGK cutting rules in general are violated in multigluon production. However we
present an argument to the effect that for doubly inclusive cross section the
AGK diagramms give the leading contribution at high energy, while genuine
violation only occurs for triple and higher inclusive gluon production. We
discuss some general properties of our expressions and suggest a line of
argument to simplify the approach further.Comment: 32 pages, one reference corrected. to appear in JHE
Fermionic Operators from Bosonic Fields in 3+1 Dimensions
We present a construction of fermionic operators in 3+1 dimensions in terms
of bosonic fields in the framework of . The basic bosonic variables are
the electric fields and their conjugate momenta . Our construction
generalizes the analogous constuction of fermionic operators in 2+1 dimensions.
Loosely speaking, a fermionic operator is represented as a product of an
operator that creates a pointlike charge and an operator that creates an
infinitesimal t'Hooft loop of half integer strength. We also show how the axial
transformations are realized in this construction.Comment: 8 pages, two figures available on request, LA-UR-94-286
SUSY 3D Georgi-Glashow model at finite temperature
We study the finite-temperature properties of the supersymmetric version of
(2+1)D Georgi-Glashow model. As opposed to its nonsupersymmetric counterpart,
the parity symmetry in this theory at zero temperature is spontaneously broken
by the bilinear photino condensate. We find that as the temperature is raised,
the deconfinement and the parity restoration occur in this model at the same
point . The transition is continuous, but is not of the Ising
type as in nonsupersymmetric Georgi-Glashow model, but rather of the
Berezinsky-Kosterlitz-Thouless type as in -invariant spin model.Comment: 8 pages, LaTeX2e, no figure
Particle Production at High Energy and Large Transverse Momentum - "The Hybrid Formalism" Revisited
We revisit the "`hybrid formalism"' for particle production used recently to
study saturation effects in single hadron multiplicities at forward rapidities
at RHIC and LHC. We point out that at leading twist there is an extra
contribution to the formulae used so far, which corresponds to particle
production via inelastic scattering of the projectile partons on the target
fields. This contribution is expected to be small due to kinematics at very
forward rapidities/very high transverse momenta, but should be significant at
high momenta and very high energies. This contribution is expected to be most
affected by saturation effects and is therefore an interesting object of study
in the context of possible onset of saturation at high energies
Bosonization in 2+1 dimensions without Chern - Simons attached
We perform the complete bosonization of 2+1 dimensional QED with one
fermionic flavor in the Hamiltonian formalism. The fermion operators are
explicitly constructed in terms of the vector potential and the electric field.
We carefully specify the regularization procedure involved in the definition of
these operators, and calculate the fermionic bilinears and the energy -
momentum tensor. The algebra of bilinears exhibits the Schwinger terms which
also appear in perturbation theory. The bosonic Hamiltonian density is a local
polynomial function of and , and we check explicitly the Lorentz
invariance of the resulting bosonic theory. Our construction is conceptually
very similar to Mandelstam's construction in 1+1 dimensions, and is dissimilar
from the recent bosonization attempts in 2+1 dimensions which hinge crucially
on the existence of a Chern - Simons term.Comment: 12 pages, LA-UR-93-1062, some misprints and algebraic errors
corrected, several comments adde
Fermions from photons: Bosonization of QED in 2+1 dimensions
We perform the complete bosonization of 2+1 dimensional QED with one
fermionic flavor in the Hamiltonian formalism. The Fermi operators are
explicitly constructed in terms of the vector potential and the electric field.
We carefully specify the regularization procedure involved in the definition of
these operators, and calculate the fermionic bilinears and the energy -
momentum tensor. The algebra of bilinears exhibits the Schwinger terms which
also appear in perturbation theory. The bosonic Hamiltonian is a local,
polynomial functional of and , and we check explicitly the Lorentz
invariance of the resulting bosonic theory. Our construction is conceptually
very similar to Mandelstam's construction in 1+1 dimensions, and is dissimilar
from the recent bosonization attempts in 2+1 dimensions, which hinge crucially
on the presence of a Chern - Simons term.Comment: 30 pages, LA - UR - 93 - 200
From bubbles to foam: dilute to dense evolution of hadronic wave function at high energy
We derive the evolution of a hadronic light cone wave function with energy at
weak coupling. Our derivation is valid both in the high and the low partonic
density limit, and thus encompasses both the JIMWLK and the KLWMIJ evolution.
The hadronic wave function is shown to evolve by the action of the
Bogoliubov-type operator, which diagonalizes on the soft gluon sector the
light-cone hamiltonian in the presence of an arbitrary valence charge density.
We find explicitly the action of this operator on the soft as well as the
valence degrees of freedom of the theory.Comment: 30 page
The Higgs field and the ultraviolet behaviour of the vortex operator in 2+1 dimensions
We calculate the change in the ultraviolet behaviour of the vortex operator
due to the presence of dynamical Higgs field in both 2+1 dimensional QED and
the 2+1 dimensional Georgi-Glashow model. We find that in the QED case the
presence of the Higgs field leads at the one loop level to power like
correction to the propagator of the vortex operator. On the other hand, in the
Georgi-Glashow model, the adjoint Higgs at one loop has no affect on the vortex
propagator. Thus, as long as the mass of the Higgs field is much larger than
the gauge coupling constant, the ultraviolet behaviour of the vortex operator
in the Georgi-Glashow model is independent of the Higgs mass.Comment: 14 page
More on eikonal approximation for high energy scattering
We formulate eikonal approximation to the calculation of high energy
scattering amplitude in the frame where both colliding objects are very
energetic. We express the eikonal scattering matrix in terms of the color
charge densities of the colliding objects. The calculation is performed in the
Hamiltonian formalism. We also show that the appearance of the longitudinal
electric and magnetic fields immediately following the collision is fully taken
into account in the eikonal approximation
A Candidate for Exact Continuum Dual Theory for Scalar QED
We discuss a possible exact equivalence of the Abelian Higgs model and a
scalar theory of a magnetic vortex field in 2+1 dimensions. The vortex model
has a current - current interaction and can be viewed as a strong coupling
limit of a massive vector theory. The fixed point structure of the theory is
discussed and mapped into fixed points of the Higgs model.Comment: 17 pages, 1 figure available on request, LA-UR-93-83
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