Coulomb photon

Fig. 3.2. Kernels with many spaimed Coulomb photons...

Fig. 3.8. Skeleton diagram with two exchanged Coulomb photons...

Note the similarity of this discussion to the consideration of the level shift induced by the polarization insertion in the external Coulomb photon in Sect. 2.2. However, unlike the present case the polarization insertion leads to a negative contribution to the energy levels since the polarization cloud screens the source charge. 

Fig. 7.3. Three-loop polarization insertions in the Coulomb photon...

Diagrams with Radiative Photon and Electron-Loop Polarization Insertion in the Coulomb Photon. Contribution of Order a (Za) m... 

Contribution of the mixed polarization graph with one electron- and one muon-loop insertions in the Coulomb photon in Fig. 7.10 may be easily calculated by the same methods as the contributions of purely electron loops, and... 

This momentum space potential is similar to the momentum space potential corresponding to insertion of the electron-loop polarization in the Coulomb photon, considered in Subsubsect. 7.1.1.1. The only difference is in the overall multiplicative constant, and that the respective expression in the case of the one electron polarization insertion contains in the denominator instead of k in (7.46). This means that the mixed loop contribution is suppressed in comparison with the purely electron loops by an additional recoil factor... 

Due to the additional recoil factor (mg/m) this contribution is suppressed by four orders of magnitude in comparison with the nonrecoil corrections generated by insertion of two electron loops in the Coulomb photon (compare (7.12)). Numerically, for the 2P — 2S interval we obtain... 

Insertion of One Electron and One Hadron Loops in the Same Coulomb Photon... 

Fig. 1. Feynman diagrams representing various contributions to the Lamb shift. A solid line represents an electron, a wavy line a virtual photon and a cross denotes exchange of a Coulomb photon (a) Leading self-energy term (b) One-loop vacuum polarisation term. The loop represents a virtual electron-positron pair (c) Some diagrams contributing to the two-loop binding correction...

The relativistic correction to the fermion kinetic energy is represented as a potential. The Breit-Fermi interaction includes the effects of transverse photon exchange as well as relativistic corrections to Coulomb photon exchange. The potentials are given with the assumption that the states acted on are S states with total spin 1. 

Fig. 1. Two-electron Feynman diagrams representing electron interaction in the second order. Solid line corresponds to electrons, dotted line corresponds to the Coulomb photons, wavy line corresponds to transverse photons (Breit interaction). If A = A and B1 = B then the diagram is called direct , otherwise, if A = B and B = A the diagram is called exchange . Letters A, B denote one-electron state...

In Coulomb gauge the expression for the Coulomb photon propagator and for the transverse photon propagator are ... 

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