arXiv subjects

O Voskresenskaya

Publications and source records attributed to O Voskresenskaya.

4 recordsLinked to original sources

arXiv2018

Coulomb correction to the spectral bremsstrahlung rate in the quantum Migdal theory of the Landau-Pomeranchuk effect

High-energy Coulomb corrections (CCs) to some quantities of the quantum Migdal theory of the Landau-Pomeranchuk-Migdal (LPM) effect are obtained analytically and numerically for the regimes of small and strong LPM suppression on the basis of a refined Moliere multiple scattering theory. Numerical calculations are presented in the ranges of the nuclear charge number Z of a scatterer from 6 to 92 and the expansion parameter B of Moliere from 4.5 to 8.5. It is shown that the relative CC to the spectral bremsstrahlung rate can reach a value of the order of -19% in the ranges considered and must be borne in mind, e.g., in the Monte-Carlo analysis of electromagnetic cascade LPM showers in extremely high-energy region.

hep-ph↗

arXiv2016

Coherent production of the long-lived pionium nP states in relativistic nucleus-nucleus collisions

The coherent production of the nP states of the $π^+π^-$ atoms ($A_{2π}$) in relativistic nucleus-nucleus collisions is considered as a possible source of the $A_{2π}(nP)$ beam for the pionium Lamb-shift measurement. A general expression for estimation of the $A_{2π}(nP)$ yield is derived in the framework of the equivalent photon approximation.

hep-ph↗

arXiv2004

Dynamics of the Pionium with the Density Matrix Formalism

The evolution of pionium, the $π^+ π^-$ 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.

physics.atom-ph↗

arXiv2003

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.

hep-ph↗