14 research outputs found
The Use of Dispersion Relations in the and Coupled-Channel System
Systematic and careful studies are made on the properties of the IJ=00
and coupled-channel system, using newly derived dispersion
relations between the phase shifts and poles and cuts. The effects of nearby
branch point singularities to the determination of the resonance are
estimated and and discussed.Comment: 22 pages with 5 eps figures. A numerical bug in previous version is
fixed, discussions slightly expanded. No major conclusion is change
Photonuclear interactions at very high energies and vector meson dominance
We show that nucleon electromagnetic structure functions of deep inelastic
scattering in Regge-Gribov limit (fixed Q-squared, asymptotically large 1/x and
s) can be well described in the two-component (soft + hard) approach. In the
concrete model elaborated by authors, the soft part of the virtual
photon-nucleon scattering is given by the vector meson dominance, with taking
into account the radial excitations of the rho-meson and nondiagonal
transitions in meson-nucleon interactions. The hard part is calculated by using
the dipole factorization, i.e., the process is considered as the dissociation
of the photon into a q and anti-q - pair (the "color dipole") and the
subsequent interaction of this dipole with the nucleon. The dipole cross
section has a Regge-type s-dependence and vanishes in the limit of large
transverse sizes of the dipole. We give the brief description of the model and
present results of the detailed comparison of model predictions with
experimental data for electromagnetic structure functions of the nucleon.Comment: 6 pages, 4 figures, the revised version prepared for a publication in
Proceedings of 23rd European Cosmic Ray Symposiu
-invariant two-fermion Dirac equation with extended hyperfine operator
For the S-states of muonium and positronium, the hyperfine shifts to the
order of a recently derived two-fermion equation with explicit -invariance are checked against the results of a nonrelativistic reduction,
and the leading shifts are calculated. An additional hyperfine
operator is discovered which can milden the singularity for of the
Dirac hyperfine operator, such that the resulting extended operator can be used
nonperturbatively. The binding correction to magnetic moments is mentioned
The bang of a white hole in the early universe from a 6D vacuum state: Origin of astrophysical spectrum
Using a previously introduced model in which the expansion of the universe is
driven by a single scalar field subject to gravitational attraction induced by
a white hole during the expansion (from a 6D vacuum state), we study the origin
of squared inflaton fluctuations spectrum on astrophysical scales.Comment: Final version to be published in Eur. Phys. J.
Analysis of inter-quark interactions in classical chromodynamics
The QCD gluon equation of motion is solved approximately by means of the
Green function. This solution is used to reformulate the Lagrangian of QCD such
that the gluon propagator appears directly in the interaction terms of the
Lagrangian. The nature of the interactions is discussed. Their coordinate-space
form is presented and analyzed in the static, non-relativistic case.Comment: 10 pages, 1 figure, LaTex2
Bogolyubov Quasiparticles in Constrained Systems
The paper is devoted to the formulation of quantum field theory for an early
universe in General Relativity considered as the Dirac general constrained
system. The main idea is the Hamiltonian reduction of the constrained system in
terms of measurable quantities of the observational cosmology: the world proper
time, cosmic scale factor, and the density of matter. We define " particles" as
field variables in the holomorphic representation which diagonalize the
measurable density. The Bogoliubov quasiparticles are determined by
diagonalization of the equations of motion (but not only of the initial
Hamiltonian) to get the set of integrals of motion (or conserved quantum
numbers, in quantum theory). This approach is applied to describe particle
creation in the models of the early universe where the Hubble parameter goes to
infinity.Comment: 13 pages, Late
Proton–nucleus scattering approximations and implications for LHC crystal collimation
In particle accelerators, scattered protons with energies close to the incident particles may travel considerable distances with the beam before impacting on accelerator components downstream. To analyze such problems, angular deflection and energy loss of scattered particles are the main quantities to be simulated since these lead to changes in the beam's phase space distribution and particle loss. Simple approximations for nuclear scattering processes causing limited energy loss to high-energy protons traversing matter are developed which are suitable for rapid estimates and reduced-description Monte Carlo simulations. The implications for proton loss in the Large Hadron Collider due to nuclear scattering on collimation crystals are discussed