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Valery A. Shelyuto

Publications and source records attributed to Valery A. Shelyuto.

33 records · Page 2Linked to original sources
arXiv2009

Radiative-Recoil Corrections to Hyperfine Splitting: Polarization Insertions in the Muon Factor

We consider three-loop radiative-recoil corrections to hyperfine splitting in muonium due to insertions of one-loop polarization operator in the muon factor. The contribution produced by electron polarization insertions are enhanced by the large logarithm of the electron-muon mass ratio. We obtained all single-logarithmic and nonlogarithmic radiative-recoil corrections of order $α^3(m/M)E_F$ generated by the diagrams with electron and muon polarization insertions.

hep-ph↗
arXiv2006

Three-Loop Radiative Corrections to Lamb Shift and Hyperfine Splitting

We consider three-loop radiative corrections to the Lamb shift and hyperfine splitting. Corrections of order $α^3(Zα)^5m$ are the largest still unknown contributions to the Lamb shift in hydrogen. We calculated radiative corrections to the Lamb shift and hyperfine splitting generated by the diagrams with insertions of one radiative photon and electron polarization loops in the graphs with two external photons. We also obtained corrections generated by the gauge invariant sets of diagrams with two reducible radiative photon insertions in the electron line and polarization operator insertion in one of the radiative photons, and diagrams with two reducible radiative photon insertions in the electron line and polarization operator insertion in one the external photons. Corrections to the Lamb shift and hyperfine splitting generated by the diagrams with insertions of the three-loop one-particle reducible diagrams with radiative photons in the electron line are calculated in the Yennie gauge.

physics.atom-ph↗
arXiv2004

Three-Loop Radiative-Recoil Corrections to Hyperfine Splitting in Muonium

We consider three-loop radiative-recoil corrections to hyperfine splitting in muonium. These corrections are enhanced by the large logarithm of the electron-muon mass ratio. The leading logarithm cubed and logarithm squared contributions were obtained a long time ago. We calculate the single-logarithmic and nonlogarithmic contributions of order $α^3(m/M)E_F$ generated by gauge invariant sets of diagrams with one- and two-loop polarization insertions in diagrams with two exchanged photons and radiative photons, and by diagrams with one-loop radiative photon insertions both in the electron and muon lines. The results of this paper constitute a next step in the implementation of the program of reduction of the theoretical uncertainty of hyperfine splitting below 10 Hz. They improve the theory of hyperfine splitting, and affect the value of the electron-muon mass ratio extracted from experimental data on the muonium hyperfine splitting.

hep-ph↗
arXiv2004

Three-Loop Radiative-Recoil Corrections to Hyperfine Splitting Generated by One-Loop Fermion Factors

We consider three-loop radiative-recoil corrections to hyperfine splitting in muonium generated by diagrams with one-loop radiative photon insertions both in the electron and muon lines. An analytic result for these nonlogarithmic corrections of order $α(Z^2α)(Zα)(m/M)\widetilde E_F$ is obtained. This result constitutes a next step in the implementation of the program of reduction of the theoretical uncertainty of hyperfine splitting below 10 Hz.

hep-ph↗
arXiv2003

New Polarization Operator Contributions to Lamb Shift and Hyperfine Splitting

We calculate radiative corrections to the Lamb shift of order $α^3(Zα)^5m$ and radiative corrections to hyperfine splitting of order $α^3(Zα)E_F$ generated by the diagrams with insertions of radiative photons and electron polarization loops in the graphs with two external photons. We also obtain the radiative-recoil correction to hyperfine splitting in muonium generated by the diagrams with the $τ$ polarization loop.

hep-ph↗
arXiv2003

Three-Loop Radiative-Recoil Corrections to Hyperfine Splitting in Muonium

We calculate three-loop radiative-recoil corrections to hyperfine splitting in muonium generated by the diagrams with the first order electron and muon polarization loop insertions in graphs with two exchanged photons. These corrections are enhanced by the large logarithm of the electron-muon mass ratio. The leading logarithm squared contribution was obtained a long time ago. Here we calculate the single-logarithmic and nonlogarithmic contributions. We previously calculated the three-loop radiative-recoil corrections generated by two-loop polarization insertions in the exchanged photons. The current paper therefore concludes calculation of all three-loop radiative-recoil corrections to hyperfine splitting in muonium generated by diagrams with closed fermion loop insertions in the exchanged photons. The new results obtained here improve the theory of hyperfine splitting, and affect the value of the electron-muon mass ratio extracted from experimental data on the muonium hyperfine splitting.

hep-ph↗
arXiv2001

Two-Loop Polarization Contributions to Radiative-Recoil Corrections to Hyperfine Splitting in Muonium

We calculate radiative-recoil corrections of order $α^2(Zα)(m/M)E_F$ to hyperfine splitting in muonium generated by the diagrams with electron and muon polarization loops. These corrections are enhanced by the large logarithm of the electron-muon mass ratio. The leading logarithm cubed and logarithm squared contributions were obtained a long time ago. The single-logarithmic and nonlogarithmic contributions calculated here improve the theory of hyperfine splitting, and affect the value of the electron-muon mass ratio extracted from the experimental data on the muonium hyperfine splitting.

hep-ph↗
arXiv2001

One-Loop Electron Vertex in Yennie Gauge

We derive a compact Yennie gauge representation for the off-shell one-loop electron-photon vertex, and discuss it properties. This expression is explicitly infrared finite, and it has proved to be extremely useful in multiloop calculations in the QED bound state problem.

hep-ph↗
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↗
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↗
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↗
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↗
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↗