scholarly journals Estimating the radiative part of QED effects in systems with supercritical charge

2019 ◽  
Vol 201 ◽  
pp. 09010
Author(s):  
Artem Roenko ◽  
Konstantin Sveshnikov
Keyword(s):  
Virtual Photon ◽  
Effective Interaction ◽  
Superheavy Nuclei ◽  
Energy Contribution ◽  
Photon Exchange ◽  
Self Energy ◽  
Lower Continuum ◽  
Qed Effects ◽  
Electron Magnetic Moment ◽  
Dynamical Screening

The effective interaction of the electron magnetic moment anomaly with the Coulomb fileld of superheavy nuclei is investigated by taking into account its dynamical screening at small distances. The shift of the electronic levels, caused by this interaction, is considered for H-like atoms and for compact nuclear quasi-molecules, non-perturbatively both in Zα and (partially) in α/π. It is shown that the levels shift reveals a non-monotonic behavior in the region Zα 1 and near the threshold of the lower continuum decreases both with the increasing the charge and with enlarging the size of the system of Coulomb sources. The last result is generalized to the total self-energy contribution to the levels shift and so to the possible behavior of radiative QED effects with virtual photon exchange near the lower continuum in the supercritical region.

scholarly journals Perturbativity vs nonperturbativity in QED-effects for H-like atoms with Zα > 1

2017 ◽  
Vol 32 (22) ◽  
pp. 1750130 ◽  
Author(s):  
A. Roenko ◽  
K. Sveshnikov
Keyword(s):  
Growth Rate ◽  
Virtual Photon ◽  
Coulomb Field ◽  
Energy Contribution ◽  
Photon Exchange ◽  
Self Energy ◽  
Lower Continuum ◽  
Quark Structure ◽  
Qed Effects ◽  
Complete Dependence

The behavior of levels near the threshold of the lower continuum in superheavy H-like atoms with [Formula: see text], caused by the interaction [Formula: see text] of the electron’s magnetic anomaly (AMM) dynamically screened at small distances [Formula: see text], with the Coulomb field of atomic nucleus is considered by taking into account the complete dependence of electron’s wave function (WF) on [Formula: see text]. It is shown that the calculation of the contribution caused by [Formula: see text] 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 also shown that there appears some difference in results between perturbative and nonperturbative methods of accounting for the contribution from [Formula: see text] within the corresponding Dirac equation (DE) in favor of the latter. Moreover, the growth rate of the contribution from [Formula: see text] reaches its maximum at [Formula: see text], while by further increase of [Formula: see text] into the supercritical region [Formula: see text], the shift of levels caused by [Formula: see text] 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.

scholarly journals ON THE PHONON-INDUCED SUPERCONDUCTIVITY OF DISORDERED ALLOYS

1996 ◽  
Vol 10 (20) ◽  
pp. 2469-2529 ◽  
Author(s):  
A.O. ANOKHIN ◽  
M.I. KATSNELSON
Keyword(s):  
Effective Interaction ◽  
Energy Scale ◽  
Phonon Interaction ◽  
Interaction Kernel ◽  
Generating Functional ◽  
Electron Phonon Interaction ◽  
Self Energy ◽  
Disordered Alloys ◽  
Electron Phonon Coupling ◽  
Alloy Part

A model of alloy is considered which includes both quenched disorder in the electron subsystem (“alloy” subsystem) and electron-phonon interaction. For given approximate solution for the alloy part of the problem, which is assumed to be conserving in Baym’s sense, we construct the generating functional and derive the Eliashberg-type equations which are valid to the lowest order in the adiabatic parameter. The renormalization of bare electron–phonon interaction vertices by disorder is taken into account consistently with the approximation for the alloy self-energy. For the case of exact configurational averaging the same set of equations is established within the usual T-matrix approach. We demonstrate that for any conserving approximation for the alloy part of the self-energy the Anderson’s theorem holds in the case of isotropic singlet pairing provided disorder renormalizations of the electron-phonon interaction vertices are neglected. Taking account of the disorder renormalization of the electron-phonon interaction we analyze general equations qualitatively and present the expressions for Tc for the case of weak and intermediate electron-phonon coupling. Disorder renormalizations of the logarithmic corrections to the effective coupling, which arise when the effective interaction kernel for the Cooper channel has the second energy scale, as well as the renormalization of the dilute paramagnetic impurity suppression are discussed.

TEST OF NL-RA1 RELATIVISTIC EFFECTIVE INTERACTION FOR THE STRUCTURE OF DEFORMED AND SUPERHEAVY NUCLEI

2012 ◽  
Vol 21 (06) ◽  
pp. 1250055 ◽  
Author(s):  
M. RASHDAN
Keyword(s):  
Effective Interaction ◽  
Mean Field Theory ◽  
Mean Field ◽  
Superheavy Element ◽  
Decay Chain ◽  
Alpha Decay ◽  
Binding Energies ◽  
Superheavy Nuclei ◽  
Relativistic Mean Field ◽  
Relative Errors

The NL-RA1 effective interaction of the relativistic mean field theory is employed to study the structure of deformed and superheavy nuclei, using an axially deformed harmonic oscillator basis. It is found that a fair agreement with the experimental data is obtained for the binding energies (BE), deformation parameters and charge radii. Comparison with NL-Z2, NLSH and NL3 interactions show that NL-Z2 gives good binding but larger radii, while NL-SH gives good radii but larger binding. The NL-RA1 interaction is also tested for the new deformed superheavy element with Z≥98. Excellent agreement with the experimental binding is obtained, where the relative error in BEs of Cf, Fm, No, Rf, Sg and Ea (Z = 110) isotopes are found to be of the order ~0.1%. The NL3 predicted larger binding and larger relative errors ~0.2–0.5%. Furthermore, the experimental Q-values of the alpha-decay of the superheavy elements 270110, 288114 and 292116 are satisfactory reproduced by NL-RA1 interaction, where the agreement is much better than that predicted by the phenomenological mass FRDM model. Furthermore, the alpha-decay chain of element 294118 are also better reproduced by NL-RA1 interaction.

Towards numerical implementation of the relativistically covariant many-body perturbation theoryThis paper was presented at the International Conference on Precision Physics of Simple Atomic Systems, held at University of Windsor, Windsor, Ontario, Canada on 21–26 July 2008.

2009 ◽  
Vol 87 (7) ◽  
pp. 817-824 ◽  
Author(s):  
Daniel Hedendahl ◽  
Ingvar Lindgren ◽  
Sten Salomonson
Keyword(s):  
Standard Procedure ◽  
Operator Method ◽  
Vertex Correction ◽  
Many Body ◽  
Atomic Systems ◽  
Self Energy ◽  
Electron Positron ◽  
Many Body Perturbation Theory ◽  
Qed Effects ◽  
First Time

The standard procedure for relativistic many-body perturbation theory (RMBPT) is not relativistically covariant, and the effects of retardation, virtual-electron-positron-pair, and radiative effects (self-energy, vacuum polarisation, and vertex correction) — the so-called QED effects — are left out. The energy contribution from the QED effects can be evaluated by the covariant evolution operator method, which has a structure that is similar to that of RMBPT, and it can serve as a merger between QED and RMBPT. The new procedure makes it, in principle, possible for the first time to evaluate QED effects together with correlation to high order. The procedure is now being implemented, and it has been shown that the effect of electron correlation on first-order QED for He-like neon dominates heavily over second-order QED effects.

scholarly journals Experimental Separation of Virtual Photon Exchange and Electron Transfer in Interatomic Coulombic Decay of Neon Dimers

2007 ◽  
Vol 99 (15) ◽  
Author(s):  
T. Jahnke ◽  
A. Czasch ◽  
M. Schöffler ◽  
S. Schössler ◽  
M. Käsz ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Virtual Photon ◽  
Photon Exchange

Self-energy contribution to the ground state hyperfine splitting of Bi82+

JETP Letters ◽  
1996 ◽  
Vol 63 (5) ◽  
pp. 316-318 ◽  
Author(s):  
V. M. Shabaev ◽  
V. A. Yerokhin
Keyword(s):  
Ground State ◽  
Hyperfine Splitting ◽  
Energy Contribution ◽  
Self Energy
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