67 research outputs found
Ratio of productions of pi+pi-atoms to free pi+pi- pairs with account of the strong interaction in final states
The ratio of productions of pi+pi- atoms to free pi+pi- pairs is calculated
with account of the strong interaction in final states. It is shown that this
ratio is expressed via a squared ratio of the well-known Coulomb wave functions
and thus can be calculated with a high accuracy.Comment: 3 page
Sum Rules for Total Interaction Cross Sections of Relativistic Elementary Atoms with Atoms of Matter Up to Terms of Order
It is shown that -term of sum rules for the total cross sections of
interaction of elementary atoms with matter ones, obtained in ref.[Denisenko K.
and Mrowczynski S., Phys. Rev. D36 (1987) 1529] is wrong. New sum rules valid
up to terms of order are derived.Comment: 3 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.
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
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
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"
The electromagnetic effects in decay
The final state interaction of pions in decay allows one to obtain
the value of the isospin and angular momentum zero scattering length
.We take into account the electromagnetic interaction of pions and
isospin symmetry breaking effects caused by different masses of neutral and
charged pions and estimate the impact of these effects on the procedure of
scattering length extraction from decay.Comment: 8 pages,1 figur
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