383 research outputs found
Ultraviolet Behavior of the Gluon Propagator in the Maximal Abelian Gauge
The ultraviolet asymptotic behavior of the gluon propagator is evaluated in
the maximal Abelian gauge in the SU(2) gauge theory on the basis of the
renormalization-group improved perturbation theory at the one-loop level.
Square-root singularities obtained in the Euclidean domain are attributed to
artifacts of the one-loop approximation in the maximal Abelian gauge and the
standard normalization condition for the propagator used in our study. It is
argued that this gauge is essentially nonperturbative.Comment: 15 pages, 2 figure
Gravitational Waves in Relativistic Theory of Gravitation
It is shown that, in the framework of Relativistic Theory of Gravitation with
massive graviton, gravitational waves, due to the causality condition, do not
bear negative energy flows.Comment: 4 page
The Relativistic Electrodynamics Least Action Principles Revisited: New Charged Point Particle and Hadronic String Models Analysis
The classical relativistic least action principle is revisited from the
vacuum field theory approach. New physically motivated versions of relativistic
Lorentz type forces are derived, a new relativistic hadronic string model is
proposed and analyzed in detail.Comment: n/
Constrained Dynamics of Universally Coupled Massive Spin 2-spin 0 Gravities
The 2-parameter family of massive variants of Einstein's gravity (on a
Minkowski background) found by Ogievetsky and Polubarinov by excluding lower
spins can also be derived using universal coupling. A Dirac-Bergmann
constrained dynamics analysis seems not to have been presented for these
theories, the Freund-Maheshwari-Schonberg special case, or any other massive
gravity beyond the linear level treated by Marzban, Whiting and van Dam. Here
the Dirac-Bergmann apparatus is applied to these theories. A few remarks are
made on the question of positive energy. Being bimetric, massive gravities have
a causality puzzle, but it appears soluble by the introduction and judicious
use of gauge freedom.Comment: 6 pages; Talk given at QG05, Cala Gonone (Italy), September 200
How to obtain a covariant Breit type equation from relativistic Constraint Theory
It is shown that, by an appropriate modification of the structure of the
interaction potential, the Breit equation can be incorporated into a set of two
compatible manifestly covariant wave equations, derived from the general rules
of Constraint Theory. The complementary equation to the covariant Breit type
equation determines the evolution law in the relative time variable. The
interaction potential can be systematically calculated in perturbation theory
from Feynman diagrams. The normalization condition of the Breit wave function
is determined. The wave equation is reduced, for general classes of potential,
to a single Pauli-Schr\"odinger type equation. As an application of the
covariant Breit type equation, we exhibit massless pseudoscalar bound state
solutions, corresponding to a particular class of confining potentials.Comment: 20 pages, Late
Background Geometry in Gauge Gravitation Theory
Dirac fermion fields are responsible for spontaneous symmetry breaking in
gauge gravitation theory because the spin structure associated with a tetrad
field is not preserved under general covariant transformations. Two solutions
of this problem can be suggested. (i) There exists the universal spin structure
such that any spin structure associated with a tetrad field
is a subbundle of the bundle . In this model, gravitational fields
correspond to different tetrad (or metric) fields. (ii) A background tetrad
field and the associated spin structure are fixed, while
gravitational fields are identified with additional tensor fields q^\la{}_\m
describing deviations \wt h^\la_a=q^\la{}_\m h^\m_a of . One can think of
\wt h as being effective tetrad fields. We show that there exist gauge
transformations which keep the background tetrad field and act on the
effective fields by the general covariant transformation law. We come to
Logunov's Relativistic Theory of Gravity generalized to dynamic connections and
fermion fields.Comment: 12 pages, LaTeX, no figure
Nucleon-nucleon wave function with short-range nodes and high-energy deuteron photodisintegration
We review a concept of the Moscow potential (MP) of the interaction. On
the basis of this concept we derive by quantum inversion optical partial
potentials from the modern partial-wave analysis (PWA) data and deuteron
properties. Point-form (PF) relativistic quantum mechanics (RQM) is applied to
the two-body deuteron photodisintegration. Calculations of the cross-section
angular distributions cover photon energies between 1.1 and 2.5 GeV. Good
agreement between our theory and recent experimental data confirms the concept
of deep attractive Moscow potential with forbidden - and -states.Comment: 31 pages, 9 figures. typos, extended formalism, review of the Moscow
potential model adde
Preasymptotic nature of hadron scattering vs small-x HERA Data
We emphasize that recently observed regularities in hadron interactions and
deep-inelastic scattering are of preasymptotic nature and it is impossible to
make conclusions on the true asymptotic behavior of observables without
unitarization procedure. Unitarization is important and changes scattering
picture drastically.Comment: LaTeX file, 9 pages; 4 tarred, gzipped and uuencoded figures in a
separate fil
New analytic unitarization schemes
We consider two well-known classes of unitarization of Born amplitudes of
hadron elastic scattering. The standard class, which saturates at the black
disk limit includes the standard eikonal representation, while the other class,
which goes beyond the black-disk limit to reach the full unitarity circle,
includes the U matrix. It is shown that the basic properties of these schemes
are independent of the functional form used for the unitarisation, and that U
matrix and eikonal schemes can be extended to have similar properties. A common
form of unitarisation is proposed interpolating between both classes. The
correspondence with different nonlinear equations are also briefly examined.Comment: 6 pages, 10 figures, corrected typos, 1 fig. redro
Hamiltonian anomalies of bound states in QED
The Bound State in QED is described in systematic way by means of nonlocal
irreducible representations of the nonhomogeneous Poincare group and Dirac's
method of quantization. As an example of application of this method we
calculate triangle diagram . We show that
the Hamiltonian approach to Bound State in QED leads to anomaly-type
contribution to creation of pair of parapositronium by two photon.Comment: 12 pages, 2 figures. Proceedings of the conference "Symmetry Methods
in Physics XV", July 12-16, 2011, Dubna, Russi
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