arXiv subjects

V. A. Agababaev

Publications and source records attributed to V. A. Agababaev.

8 recordsLinked to original sources

arXiv2026

Quadratic Zeeman effect in light boron-like ions

The quadratic Zeeman effect is calculated for the ground $^2P_{1/2}$ state of light boron-like ions in the range of nuclear-charge numbers $Z = 10-24$. The calculations are performed in the Furry picture using three models for the zeroth-order approximation potential: pure nuclear Coulomb potential and two effective screening potentials $-$ core-Hartree and Kohn-Sham. First-order perturbation-theory contributions are considered: the one-photon-exchange correction and the radiative corrections associated with the self-energy and vacuum-polarization diagrams. The dominant contributions from the self-energy diagrams are calculated within a rigorous QED approach. The vacuum polarization corrections are obtained within the electric-loop approximation in the leading order, which is given by the Uehling potential. As a result, theoretical predictions for the contribution of the quadratic Zeeman effect to the binding energy of the valence electron in the $^2P_{1/2}$ state are obtained. The results can be used for the analysis of high-precision $g$-factor and fine-structure splitting measurements in boron-like highly charged ions.

physics.atom-ph↗

arXiv2025

QED effects in quadratic Zeeman splitting in highly charged hydrogen-like ions

We present ab initio calculations of one-electron quantum electrodynamical corrections to the second-order Zeeman splitting for the $1s_{1/2}$, $2s_{1/2}$, and $2p_{1/2}$ states in highly charged hydrogen-like ions. The self-energy correction is evaluated using the rigorous QED approach. The vacuum polarization correction is evaluated within the electric-loop approximation. Calculations are performed for the wide range of nuclear charge number: $Z = 14 - 92$.

physics.atom-ph↗

arXiv2025

$g$ factor of the $2p_j$ excited states in lithium-like ions

Relativistic calculations for the $g$ factor of the lowest excited states $2p_{1/2}$ and $2p_{3/2}$ of lithium-like ions over a wide range of the nuclear charge numbers $Z=10-92$ are presented. Interelectronic interaction is considered within the perturbation theory up to the second order. One-loop QED contributions are calculated to all orders in $αZ$. Leading contributions of the nuclear recoil effects are taken into account. The quadratic and cubic terms in magnetic field are considered as well. A set of screening potentials is used in all calculations to estimate the unknown higher-order correlation effects.

physics.atom-ph↗

arXiv2020

Helium-like ions in magnetic field: application of the nonperturbative relativistic method for axially symmetric systems

Dirac equation for an electron bound by a nucleus in the presence of external axially symmetric field can be solved numerically by using the dual-kinetic-balance conditions imposed on the finite basis set (A-DKB method [Rozenbaum et al, Phys. Rev. A 89, 012514 (2014)]). We present the application of this method to describe helium-like ions exposed to homogeneous external magnetic field. The second-order Zeeman shift and the nuclear magnetic shielding constant are evaluated for the ground state, including the leading contribution of the interelectronic interaction. The A-DKB values are compared with the direct calculations by perturbation theory. The results for the nuclear magnetic shielding can serve for accurate determination of the nuclear magnetic moments. The quadratic contribution to the Zeeman effect can be relevant for high-precision measurements of the transition energies in helium-like ions.

physics.atom-ph↗

arXiv2019

$g$ factor of the $[(1s)^2(2s)^2 2p]~{}^2P_{3/2}$ state of middle-$Z$ boronlike ions

Theoretical \emph{g}-factor calculations for the first excited \exst state of boronlike ions in the range $Z$=10--20 are presented and compared to the previously published values. The first-order interelectronic-interaction contribution is evaluated within the rigorous QED approach in the effective screening potential. The second-order contribution is considered within the Breit approximation. The QED and nuclear recoil corrections are also taken into account.

physics.atom-ph↗

arXiv2019

$g$-factor of Boronlike Argon $^{40}\textrm{Ar}^{13+}$

We have measured the ground-state $g$-factor of boronlike argon $^{40}\textrm{Ar}^{13+}$ with a fractional uncertainty of \SI{1.4e-9}{} with a single ion in the newly developed ALPHATRAP double Penning-trap setup. The here obtained value of $g=0.663\,648\,455\,32(93)$ is in agreement with our theoretical prediction of $0.663\,648\,12(58)$. The latter is obtained accounting for quantum electrodynamics, electron correlation, and nuclear effects within the state-of-the-art theoretical methods. Our experimental result distinguishes between existing predictions that are in disagreement, and lays the foundations for an independent determination of the fine-structure constant.

physics.atom-ph↗

arXiv2018

Ground-state $g$ factor of middle-$Z$ boronlike ions

Theoretical calculations of the interelectronic-interaction and QED corrections to the $g$ factor of the ground state of boronlike ions are presented. The first-order interelectronic-interaction and the self-energy corrections are evaluated within the rigorous QED approach in the effective screening potential. The second-order interelectronic interaction is considered within the Breit approximation. The nuclear recoil effect is also taken into account. The results for the ground-state $g$ factor of boronlike ions in the range $Z$=10--20 are presented and compared to the previous calculations.

physics.atom-ph↗

arXiv2018

Interelectronic-interaction contribution to the nonlinear Zeeman effect in boronlike ions

Relativistic calculations of the second- and third-order contributions in magnetic field to the Zeeman splitting in boronlike ions are presented for the wide range of nuclear charge numbers $Z=6$--$92$. The interelectronic-interaction correction of the first order in $1/Z$ is evaluated to all orders in $αZ$. The higher-order corrections in $1/Z$ are taken into account approximately by means of effective screening potentials. The obtained results are important for interpretation of experimental data on the Zeeman splitting in boronlike ions, in particular, for the ARTEMIS experiment presently implemented at GSI.

physics.atom-ph↗