212,422 research outputs found
Classical Aspects of the Abelian Higgs Model on the Light Front
We investigate canonical structure of the Abelian Higgs model within the
framework of DLCQ. Careful boundary analysis of differential equations, such as
the Euler-Lagrange equations, leads us to a novel situation where the canonical
structure changes in a drastic manner depending on whether the (light-front)
spatial Wilson line is periodic or not. In the former case, the gauge-field ZM
takes discrete values and we obtain the so-called ``Zero-Mode Constraints''
(ZMCs), whose semiclassical solutions give a nonzero vev to the scalar fields.
Contrary, in the latter case, we have no ZMC and the scalar ZMs remain
dynamical as well as the gauge-field ZM. In order to give classically nonzero
vev to the scalar field, we work in a background field which minimizes the
light-front energy.Comment: 10 pages, reference modifie
Spectrum of Two-Dimensional (Super)Gravity
We review the BRST analysis of the system of a (super)conformal matter
coupled to 2D (super)gravity. The spectrum and its operator realization are
reported. In particular, the operators associated with the states of nonzero
ghost number are given. We also discuss the ground ring structure of the
super-Liouville coupled to matter. In appendices, hermiticities,
states for conformal matter coupled to gravity and the proof for the
spectrum are discussed.Comment: 34 page
QCD at Finite temperature and density with staggered and Wilson quarks
One of the most challenging issues in particle physics is to study QCD in
extreme conditions. Precise determination of the QCD phase diagram on
temperature and chemical potential plane will provide valuable
information for quark-gluon plasma (QGP) and neutron star physics. We present
results for phase structure on the plane for lattice QCD with Wilson
fermions from strong coupling Hamiltonian analysis and Kogut-Susskind Fermions
from Lagrangian Monte Carlo simulations at intermediate coupling.Comment: Lattice 2004 (nonzero
Spin angular impulse due to spin-dependent reflection off a barrier
The spin-dependent elastic reflection of quasi two-dimensional electrons from
a lateral impenetrable barrier in the presence of band-structure spin-orbit
coupling results in a spin angular impulse exerted on the electrons which is
proportional to the nontrivial difference between the electrons' momentum and
velocity. Even for an unpolarized incoming beam we find that the spin angular
impulse is nonzero when averaged over all components of the reflected beam. We
present a detailed analysis of the kinematics of this process.Comment: 4 pages, 2 figures, final versio
Anisotropic flows from initial state of a fast nucleus
We analyze azimuthal anisotropy in heavy ion collisions related to the
reaction plane in terms of standard reggeon approach and find that it is
nonzero even when the final state interaction is switched off. This effect can
be interpreted in terms of partonic structure of colliding nuclei. We use
Feynman diagram analysis to describe details of this mechanism. Main
qualitative features of the appropriate azimuthal correlations are discussed.Comment: 16 pages, 11 figures. This paper is an extended version of a talk
given at Session of Nuclear Physics Division of Russian Academy of Sciences
in November 200
Spectral theory of a Neumann-Poincar\'e-type operator and analysis of anomalous localized resonance II
If a body of dielectric material is coated by a plasmonic structure of
negative dielectric constant with nonzero loss parameter, then cloaking by
anomalous localized resonance (CALR) may occur as the loss parameter tends to
zero. The aim of this paper is to investigate this phenomenon in two and three
dimensions when the coated structure is radial, and the core, shell and matrix
are isotropic materials. In two dimensions, we show that if the real part of
the permittivity of the shell is -1 (under the assumption that the permittivity
of the background is 1), then CALR takes place. If it is different from -1,
then CALR does not occur. In three dimensions, we show that CALR does not
occur. The analysis of this paper reveals that occurrence of CALR is determined
by the eigenvalue distribution of the Neumann-Poincar\'e-type operator
associated with the structure
A Review of Target Mass Corrections
With recent advances in the precision of inclusive lepton--nuclear scattering
experiments, it has become apparent that comparable improvements are needed in
the accuracy of the theoretical analysis tools. In particular, when extracting
parton distribution functions in the large-x region, it is crucial to correct
the data for effects associated with the nonzero mass of the target. We present
here a comprehensive review of these target mass corrections (TMC) to structure
functions data, summarizing the relevant formulas for TMCs in electromagnetic
and weak processes. We include a full analysis of both hadronic and partonic
masses, and trace how these effects appear in the operator product expansion
and the factorized parton model formalism, as well as their limitations when
applied to data in the x->1 limit. We evaluate the numerical effects of TMCs on
various structure functions, and compare fits to data with and without these
corrections.Comment: 41 pages, 13 figures; minor updates to match published versio
There are no magnetically charged particle-like solutions of the Einstein Yang-Mills equations for Abelian models
We prove that there are no magnetically charged particle-like solutions for
Abelian models in Einstein Yang-Mills, but for non-Abelian models the
possibility remains open. An analysis of the Lie algebraic structure of the
Yang-Mills fields is essential to our results. In one key step of our analysis
we use invariant polynomials to determine which orbits of the gauge group
contain the possible asymptotic Yang-Mills field configurations. Together with
a new horizontal/vertical space decomposition of the Yang-Mills fields this
enables us to overcome some obstacles and complete a dynamical system existence
theorem for asymptotic solutions with nonzero total magnetic charge. We then
prove that these solutions cannot be extended globally for Abelian models and
begin an investigation of the details for non-Abelian models.Comment: 48 pages, 1 figur
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