227 research outputs found
Contribution of -terms to the total interaction cross sections of relativistic elementary atoms with atoms of matter
It is shown that the corrections of order to the total cross
sections for interaction of elementary hydrogen-like atoms with target atoms,
reported in the previously published paper [S.Mrowczynski, Phys.Rev. D36, 1520
(1987)], do not include some terms of the same order of magnitude. That results
in a significant contribution of these corrections in particular cases. The
full -corrections have been derived and it is shown that they are
really small and could be omitted for most practical applications.Comment: 5 page
Dynamics of the Pionium with the Density Matrix Formalism
The evolution of pionium, the hydrogen-like atom, while passing
through matter is solved within the density matrix formalism in the first Born
approximation. We compare the influence on the pionium break-up probability
between the standard probabilistic calculations and the more precise picture of
the density matrix formalism accounting for interference effects. We focus our
general result in the particular conditions of the DIRAC experiment at CERN.Comment: 14 pages, 2 figures, submitted to J. Phys. B: At. Mol. Phy
Density Matrix Kinetic Equation Describing a Passage of Fast Atomic Systems Through Matter
The quantum-mechanical consideration of a passage of fast dimesoatoms through
matter is given. A set of quantum-kinetic equations for the density matrix
elements describing their internal state evolution is derived. It is shown that
probabilistic description of internal dynamics of hydrogen-like atoms is
impossible even at sufficiently low energies because of the ``accidental''
degeneracy of their energy levels.Comment: 12 pages, LATEX, submitted to J. Phys.
Theoretical Predictions for Pionium Searches
Characteristic properties of pionium and associated low energy
s--wave cross sections ,
and are
investigated with a coupled channels potential model. Some experimental results
and conclusions are to be reconsidered.Comment: 10 Pages REVTeX using epsfig.sty. Submitted to PR
The Coulomb Interaction between Pion-Wavepackets: The piplus-piminus Puzzle
The time dependent Schr\"odinger equation for -- pairs, which
are emitted from the interaction zone in relativistic nuclear collisions, is
solved using wavepacket states. It is shown that the Coulomb enhancement in the
momentum correlation function of such pairs is smaller than obtained in earlier
calculations based on Coulomb distorted plane waves. These results suggest that
the experimentally observed positive correlation signal cannot be caused by the
Coulomb interaction between pions emitted from the interaction zone. But other
processes which involve long-lived resonances and the related extended source
dimensions could provide a possible explanation for the observed signal.Comment: 12 pages, LaTeX, 1 figur
Direct calculation of the probability of pionium ionization in the target
We performed the first direct calculation of the probability of pionium
(pi+pi- atom) ionization in the target. The dependence of the probability of
pionium ionization in the target as a function of the pionium lifetime is
established. These calculations are of interest of the DIRAC experiment at
CERN, which aims to measure the pionium lifetime with high precision.Comment: 11 pages, 4 figures; submitted to "Physics of Atomic Nuclei"
("Yadernaya Fizika"
Perturbative framework for the pi(+)pi(-) atom
The perturbative framework is developed for the calculation of the pi(+)pi(-)
atom characteristics on the basis of the field-theoretical Bethe-Salpeter
approach. A closed expression for the first-order correction to the pi(+)pi(-)
atom lifetime has been obtained.Comment: 8 pages, LaTeX-fil
Hadronic Atoms and Effective Interactions
We examine the problem of hadronic atom energy shifts using the technique of
effective interactions and demonstrate equivalence with the conventional
quantum mechanical approach.Comment: 22 page latex file with 2 figure
A Complete Version of the Glauber Theory for Elementary Atom - Target Atom Scattering and Its Approximations
A general formalism of the Glauber theory for elementary atom (EA) - target
atom (TA) scattering is developed. A second-order approximation of its complete
version is considered in the framework of the optical-model perturbative
approach. A `potential' approximation of a second-order optical model is
formulated neglecting the excitation effects of the TA. Its accuracy is
evaluated within the second-order approximation for the complete version of the
Glauber EA-TA scattering theory.Comment: PDFLaTeX, 10 pages, no figures; an updated versio
Mobile Data Repositories at the Edge.
In a future IoT-dominated environment the majority of
data will be produced at the edge, which may be moved
to the network core. We argue that this reverses today’s
“core-to-edge” data flow to an “edge-to-core” model
and puts severe stress on edge access/cellular links. In
this paper, we propose a data-centric communication approach
which treats storage and wire the same as far as
their ability to supply the requested data is concerned.
Given that storage is cheaper to provide and scales better
than wires, we argue for enhancing network connectivity
with local storage services (e.g., in WiFi Access Points,
or similar) at the edge of the network. Such local storage
services can be used to buffer IoT and user-generated
data at the edge, prior to data-cloud synchronization
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