arXiv subjects

K. A. Sveshnikov

Publications and source records attributed to K. A. Sveshnikov.

3 recordsLinked to original sources

arXiv2024

Magnetic vacuum polarization effects in the supercritical QED: spontaneous generation of a stable highly magnetized phase of the vacuum state

The spontaneous generation of axial vacuum current and corresponding magnetic field with multipole structure, caused by the supercritical Coulomb source with charge $Z$ and size $R$, is explored in essentially non-perturbative approach with emphasis on the vacuum energy $\cal{E}_{VP}$, considered as a function of $R$ with fixed $Z$. The properties of such highly magnetized vacuum phase are studied in detail. It is shown that the arising this way magnetic component of the supercritical vacuum polarization leads to a significant decrease of the total energy of the system, which could provide the formation of a stable extra-heavy nuclear cluster. Numerical calculations proving the latter in case of the specific spherically symmetric Coulomb source with $Z = 828$ are presented.

hep-ph↗

arXiv2018

Estimating the radiative part of QED effects in superheavy nuclear quasimolecules

A method for calculating the electronic levels in the compact superheavy nuclear quasi-molecules, based on solving the two-center Dirac equation using the multipole expansion of two-center potential, is developed. For the internuclear distances up to $d\sim100$~fm such technique reveals a quite fast convergence and allows for computing the electronic levels in such systems with accuracy $\sim 10^{-6} $. The critical distances $R_{cr}$ between the nuclei for $1σ_g$ and $1σ_u$ electronic levels in the region $Z\simeq 87-100$ are calculated. By means of the same technique the shifts of electronic levels due to the effective interaction $ΔU_{AMM}$ of the electron's magnetic anomaly with the Coulomb field of the closely spaced heavy nuclei are evaluated as a function of the internuclear distance and the charge of the nuclei, non-perturbatively both in $Zα$ and (partially) in $α/π$. It is shown, that the levels shifts near the lower continuum decrease with the enlarging size of the system of Coulomb sources both in the absolute units and in units of $Z^4 α^5 / πn^3$. The last result is generalized to the whole self-energy contribution to the level shifts and so to the possible behavior of radiative part of QED-effects with virtual photon exchange near the lower continuum in the overcritical region.

physics.atom-ph↗

arXiv2017

Perturbativity vs non-perturbativity in QED-effects for H-like atoms with $Zα>1$

The behavior of levels near the threshold of the lower continuum in superheavy H-like atoms with $Zα>1$, caused by the interaction $ΔU_{AMM}$ of the electron's magnetic anomaly (AMM) dynamically screened at small distances $ \ll 1/m$, with the Coulomb field of atomic nucleus is considered by taking into account the complete dependence of electron's wavefunction (WF) on $Zα$. It is shown that the calculation of the contribution caused by $ΔU_{AMM}$ via both the quark structure and the whole nucleus, considered as a uniformly charged extended Coulomb source, leads to results, which coincide within the accepted precision of calculations. It is shown also that there appears some difference in results between perturbative and non-perturbative methods of accounting for the contribution from $ΔU_{AMM}$ within the corresponding Dirac equation (DE) in favor of the latter. Moreover, the growth rate of the contribution from $ΔU_{AMM}$ reaches its maximum at $ Z \sim 140-150$, while by further increase of $Z$ into the supercritical region $Z\gg Z_{cr,1}$ the shift of levels caused by $ΔU_{AMM}$ near the lower continuum decreases monotonically to zero. The last result is generalized to the whole self-energy contribution to the shift of levels and so to the possible behavior of radiative QED-effects with virtual photon exchange near the lower continuum.

physics.atom-ph↗