Olga Yu. Khetselius

Relativistic Theory of Cooperative Muon – γ-Nuclear Processes: Negative Muon Capture and Metastable Nucleus Discharge

We present a new consistent energy approach to calculation of the cross-section for the negative muon capture by an atom, based on the relativistic many-body perturbation (PT) theory. The calculation results for cross-section of the μ−capture by He atom are listed. It is presented a generalized energy approach in the relativistic theory of discharge of a metastable nucleus with emission of γ quantum and further muon conversion, which initiates this discharge. The numerical calculation of the corresponding probabilities is firstly carried out for the scandium nucleus (A = 49, N = 21) with using the Dirac-Woods-Saxon model. The theoretical and experimental studying the muon-γ-nuclear interaction effects opens prospects for nuclear quantum optics, probing the structural features of a nucleus and muon spectroscopy in atomic and molecular physics.

Gauge-Invariant QED Perturbation Theory Approach to Calculating Nuclear Electric Quadrupole Moments, Hyperfine Structure Constants for Heavy Atoms and Ions

Relativistic calculation of the spectrum hyperfine structure parameters for heavy atoms and multicharged ions with an account of the relativistic, correlation, nuclear, quantum electrodynamics (QED) effects is carried out. Our calculation method is based on the gauge-invariant QED perturbation theory (PT) with using the optimized one-quasiparticle representation firstly in the theory of the hyperfine structure for relativistic systems. The energies and constants of the hyperfine structure, derivatives of the one-electron characteristics on nuclear radius, nuclear electric quadrupole, magnetic dipole moments Q for atom of the hydrogen 1H (test calculation), superheavy H-like ion with nuclear charge Z = 170, Li-like multicharged ions with Z = 20 ÷ 100, neutral atoms of 235U, 201Hg and 227Ra are calculated.

Relativistic Quantum Chemistry of Heavy Ions and Hadronic Atomic Systems: Spectra and Energy Shifts

The levels energies and energy shifts are calculated for superheavy Li‐like ions and some kaonic atoms on the basis of the gauge‐invariant QED perturbation theory (PT) with an account of nuclear, exchange‐correlation and radiative effects.

QED Approach to Atoms in a Laser Field: Multi-Photon Resonances and Above Threshold Ionization

A new consistent method for studying the interaction of atom with a realistic laser field, based on the quantum electrodynamics (QED) and S-matrix adiabatic formalism Gell-Mann and Low, is presented. In relativistic case the Gell-Mann and Low formula expressed an energy shift δE through QED scattering matrix including the interaction with as the laser field as the photon vacuum field. It is natural to describe the laser field-atom interaction by means of the radiation emission and absorption lines. Their position and shape fully determine the spectroscopy of atom in a field. The radiation atomic lines can be described by moments of different orders μn. The main contribution into μn is given by the resonant range. The values μn can be expanded into perturbation theory (PT) series. As example, the method is used for numerical calculation of the three-photon resonant, four-photon ionization profile of atomic hydrogen (1s-2p transition; wavelength = 365 nm) and multi-photon resonance width and shift for transition 6S-6F in the atom of Cs (wavelength 1,059 nm) in a laser pulses with the Gaussian and soliton-like shapes. The results of calculation the above threshold ionization (ATI) characteristics for atom of magnesium field are presented too.

Relativistic Quantum Chemistry of Heavy Elements: Interatomic potentials and Lines Shift for Systems 'Alkali Elements-Inert Gases'

New relativistic approach, based on the gauge‐invariant perturbation theory (PT) with using the optimized wave functions basis’s, is applied to calculating the inter atomic potentials, hyper fine structure (hfs) collision shift for alkali atoms in atmosphere of inert gases. Data for inter atomic potentials, collision shifts of the Rb and Cs atoms in atmosphere of the inert gas He are presented.

New Laser-Electron Nuclear Effects in the Nuclear γ Transition Spectra in Atomic and Molecular Systems

A consistent QED perturbation theory approach is applied to calculation of the electron-nuclear γ-transition spectra of nucleus in the multicharged ion. The intensities of satellites are defined in the relativistic version of the energy approach (S-matrix formalism). As example, the nuclear transition in the isotope 26 57 Fe with energy 14.41 keV is considered. The results of the relativistic calculation for the electron-nuclear γ-transition spectra (set of electron satellites) of the nucleus in a multicharged atomic ion FeXIX are presented. The possible experiments for observation of the new effect in the thermalized plasma of O- like ions are discussed. Consistent, quantum approach to calculation of the electron-nuclear γ transition spectra (set of vibration-rotational satellites in molecule) of nucleus in molecule, which generalizes the well known Letokhov-Minogin model, is presented and based on the Dunham model potential approximation for potential curves of the diatomic molecules. Estimates are made for vibration-rotation-nuclear transition probabilities in a case of the emission and absorption spectrum of nucleus 127I (E γ (0) = 203 keV) in the molecule of H127I. Estimates of the vibration-nuclear transition probabilities in a case of the emission and absorption spectrum of nucleus 191Ir (E γ (0) = 82 keV) in the molecule of IrO4 and nucleus 188Os (E γ (0) = 155 keV) in the molecule of OsO4 are presented too.

The sea and ocean 3D acoustic waveguide: rays dynamics and chaos phenomena

It has been carried out modeling of the sea and ocean 3D acoustic waveguide. On the basis of Hamiltonian equations of rays it is studied a dynamics of rays. It has been shown that for acoustic waveguide in a shallow sea with non‐level bottom under the rays propagation in a waveguide dependence of the of temporal frequency upon the output angle represents a fractal measure in accordance with Abdullaev‐Zaslavsky result. For the ocean 3D acoustic waveguide on the basis of solving the eiconal equations in the Hamiltonian form it has been studied the fractal dynamics, including the chaotic one. There are presented the data of numerical solution of equations for the typical acoustic channel in the North‐Atlantic region. The conditions for the Arnold diffusion effect realization are discussed.