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Michael I. Eides

Publications and source records attributed to Michael I. Eides.

50 records · Page 3Linked to original sources
arXiv2000

Radiative-Recoil Corrections of Order $α(Zα)^5(m/M)m$ to Lamb Shift Revisited

The results and main steps of an analytic calculation of radiative-recoil corrections of order $α(Zα)^5(m/M)m$ to the Lamb shift in hydrogen are presented. The calculations are performed in the infrared safe Yennie gauge. The discrepancy between two previous numerical calculations of these corrections existing in the literature is resolved. Our new result eliminates the largest source of the theoretical uncertainty in the magnitude of the deuterium-hydrogen isotope shift.

hep-ph↗
arXiv2000

Theory of Light Hydrogenlike Atoms

The present status and recent developments in the theory of light hydrogenic atoms, electronic and muonic, are extensively reviewed. The discussion is based on the quantum field theoretical approach to loosely bound composite systems. The basics of the quantum field theoretical approach, which provide the framework needed for a systematic derivation of all higher order corrections to the energy levels, are briefly discussed. The main physical ideas behind the derivation of all binding, recoil, radiative, radiative-recoil, and nonelectromagnetic spin-dependent and spin-independent corrections to energy levels of hydrogenic atoms are discussed and, wherever possible, the fundamental elements of the derivations of these corrections are provided. The emphasis is on new theoretical results which were not available in earlier reviews. An up-to-date set of all theoretical contributions to the energy levels is contained in the paper. The status of modern theory is tested by comparing the theoretical results for the energy levels with the most precise experimental results for the Lamb shifts and gross structure intervals in hydrogen, deuterium, and helium ion $He^+$, and with the experimental data on the hyperfine splitting in muonium, hydrogen and deuterium.

hep-ph↗
arXiv1998

Hard Exclusive Electroproduction of Pseudoscalar Mesons and QCD axial anomaly

The hard exclusive electroproduction of $π^0,η,η'$ mesons by the longitudinal photons is considered. We calculate the ratios of the $π^0 : η: η'$ yields for the electroproduction processes off nucleons and deuterons based on the QCD factorization theorem, the low energy QCD chiral dynamics, and the QCD anomaly. Thus investigation of these ratios gives a new way to probe the physics of the spontaneous chiral symmetry breaking.

hep-ph↗
arXiv1998

Second Order in Mass Ratio Radiative-Recoil Corrections to Hyperfine Splitting in Muonium

Radiative-recoil corrections to hyperfine splitting in muonium of orders $α(Zα)(m/M)^2E_F$ and $(Z^2α)(Zα)(m/M)^2E_F$ are calculated. These corrections are of the second order in the small electron-muon mass ratio. An analytic expression $[(-6 \ln2- \frac{3}{4})α(Zα) - \frac{17}{12} (Z^2 α) (Zα)](\frac{m}{M})^2 E_F$ is obtained. Numerically the correction is equal to $-0.0351\:\mbox{kHz}$ and is of the same order of magnitude as the expected accuracy of the current Los Alamos experiment to measure the hyperfine splitting.

hep-ph↗
arXiv1997

Gyromagnetic Ratios of Bound Particles

A new approach to calculation of the binding corrections to the magnetic moments of the constituents in a loosely bound system, based on the Bargmann-Michel-Telegdi equation, is suggested. Binding corrections are calculated in this framework, and the results confirm earlier calculations performed by other methods. Our method clearly demonstrates independence of the binding corrections on the magnitude of the spin of the constituents.

hep-ph↗
arXiv1996

One More Analytic Result for $α^{2}(Zα)^{5}m$ Correction to the Lamb Shift

The analytic result for the radiative correction of order $α^{2}(Zα)^{5}m$ to the Lamb shift connected with a polarization insertion in one of the two external Coulomb lines is obtained. This correction arises from a gauge invariant set of diagrams which contain, besides the polarization insertion in the Coulomb leg, all one-loop radiative photon insertions in the electron line with two external Coulomb lines.

hep-ph↗
arXiv1996

Corrections of Order $α^6m$ to $S$-Levels of Helium

Several new corrections of order $mα^6$ to the energy levels of $S$ states in helium are obtained from radiative corrections to the Breit potential and from the polarization insertions in the two photon exchange graphs. While individual gauge invariant contributions are comparable to current experimental errors, the sum of these corrections is an order of magnitude smaller due to mutual cancellations.

hep-ph↗
arXiv1995

CORRECTIONS OF ORDER $α^2(Zα)^5$ TO HYPERFINE SPLITTING AND LAMB SHIFT

Corrections to hyperfine splitting and Lamb shift of order $α^2(Zα)^5$ induced by the diagrams with radiative photon insertions in the electron line are calculated in the Fried-Yennie gauge. These contributions are as large as $-7.725(3)α^2(Zα)^5/(πn^3)(m_r/m)^3m$ and $-0.6711(7)α^2(Zα)/(πn^3)E_F$ for the Lamb shift and hyperfine splitting, respectively. Phenomenological implications of these results are discussed with special emphasis on the accuracy of the theoretical predictions for the Lamb shift and experimental determination of the Rydberg constant. New more precise value of the Rydberg constant is obtained on the basis of the improved theory and experimental data.

hep-ph↗
arXiv1994

New Corrections of Order $α^6$ to $s$-Levels of Two-Body Systems

New corrections to the energy of $S$-levels of positronium of order $mα^6$ which are as large as several hundred kilohertz are obtained. A new recoil correction of order $α(Zα)^5(m/M)m$ to the Lamb shift in hydrogen is calculated. This correction turns out to be too small from the phenomenological point of view.

hep-ph↗
arXiv1994

An $α^{2}(Z α)^{5}m$ Contribution to the Hydrogen Lamb Shift from Virtual Light by Light Scattering

The radiative correction to the Lamb shift of order $α^{2}(Zα)^5m$ induced by the light by light scattering insertion in external photons is obtained. The new contribution turns out to be equal to $-0.122(2)α^2(Zα)^5/(πn^3)(m_r/m)^3m$. Combining this contribution with our previous results we obtain the complete correction of order $α^{2}(Zα)^5m$ induced by all diagrams with closed electron loops. This correction is $37.3(1)$ kHz and $4.67(1)$ kHz for the $1S$- and $2S$-states in hydrogen, respectively.

hep-ph↗
arXiv1993

First Corrections to Hyperfine Splitting and Lamb Shift Induced by Diagrams with Two External Photons and Second Order Radiative Insertions in the Electron Line

Contributions to HFS and to the Lamb shift intervals of order $α^2(Zα)^5$ induced by graphs with two radiative photons inserted in the electron line are considered. It is demonstrated that this last gauge invariant set of diagrams which are capable of producing corrections of considered order consists of nineteen topologically different diagrams. Contributions both to HFS and Lamb shift induced by graphs containing one-loop electron self-energy as a subgraph and also by the graph containing two one-loop vertices are obtained.

hep-ph↗