Related papers: Nonrelativistic QED approach to the Lamb shift
The results and main steps of an analytic calculation of radiative-recoil corrections of order $\alpha(Z\alpha)^5(m/M)m$ to the Lamb shift in hydrogen are presented. The calculations are performed in the infrared safe Yennie gauge. The…
We calculate the relativistic corrections of relative order (Z alpha)^2$ to the two-photon decay rate of higher excited S and D states in ionic atomic systems, and we also evaluate the leading radiative corrections of relative order alpha…
A simple but effective method for regularization-renormalization (R-R) is proposed for handling the Feynman diagram integral (FDI) at one loop level in quantum electrodynamics (QED). The divergence is substituted by some constants to be…
A calculation of the one-loop self-energy and vacuum-polarization corrections to the hyperfine splitting of the 1s and 2s states in light H-like ions is carried out to all orders in the parameter Z \alpha. Using the known values for the Z…
New corrections to the energy of $S$-levels of positronium of order $m\alpha^6$ which are as large as several hundred kilohertz are obtained. A new recoil correction of order $\alpha(Z\alpha)^5(m/M)m$ to the Lamb shift in hydrogen is…
We present results on the self-energy correction to the energy levels of hydrogen and hydrogenlike ions. The self energy represents the largest QED correction to the relativistic (Dirac-Coulomb) energy of a bound electron. We focus on the…
We consider three-loop radiative corrections to the Lamb shift and hyperfine splitting. Corrections of order $\alpha^3(Z\alpha)^5m$ are the largest still unknown contributions to the Lamb shift in hydrogen. We calculated radiative…
In [Li ${\it et \, al.}$, Phys. Rev. A ${\bf 98}$, 020502(R) (2018)] it was claimed that the model-potential computations of the Lamb shift on the $^2P_{1/2}-{}^2P_{3/2}$ fine structure in fluorinelike uranium lead to a discrepancy between…
Within a systematic approach based on the dimensionally regularized nonrelativistic quantum electrodynamics, we derive the complete result for the two-loop correction to order $(\alpha/\pi)^2 (Z \alpha)^4$ for the $g$ factor of an electron…
Methods of bound-state QED that treat the self-energy contributions to the Lamb shift within the partial-wave expansion usually face the problem of slow convergence of the latter. Inspired by an approach formulated in [J. Sapirstein and K.…
Theoretical predictions for the Lamb shift in helium are limited by unknown quantum electrodynamic effects of the order $\alpha^7m$, where $\alpha$ is the fine-structure constant and $m$ is the electron mass. We make an important step…
We report on recent progress in the treatment of two-loop binding corrections to the Lamb shift, with a special emphasis on S and P states. We use these and other results in order to infer an updated theoretical value of the Lamb shift in…
We analyze several phenomenological implications of a nonlocal generalization of quantum electrodynamics (QED). We compute the nonlocal corrections to the photon propagator up to one loop, and we show that nonlocality leads to a change of…
This work is a collection of initial calculations and formal considerations within the Salpeter-Sucher exact equal-time relativistic quantum electrodynamics framework. The calculations are carried out as preparation for the computation of…
Two-loop contributions to the electromagnetic form factors are calculated in the kinematic regime close to the fermion-antifermion threshold. The results are presented in an expansion in the velocity $\beta$ of the fermions in the c.m.…
The hyperfine structure (HFS) of a bound electron is modified by the self-interaction of the electron with its own radiation field. This effect is known as the self-energy correction. In this work, we discuss the evaluation of higher-order…
We comprehensively analyse the theoretical prediction for the Lamb shift in muonic hydrogen, and the associated determination of the proton radius. We use effective field theories. This allows us to relate the proton radius with…
We rederive the $O(\alpha^5)$ shift of the hydrogen levels in the non-recoil ($m_e/m_P \to 0$) limit using Nonrelativistic QED (NRQED), an effective field theory developed by Caswell and Lepage (Phys. Lett. 167B, 437 (1986)). Our result…
We commence the evaluation of the one- and two-loop binding corrections to the $g factor for an electron in a hydrogenlike system of order alpha^2 (Z alpha)^5 and consider diagrams with closed fermion loops. The one-loop vacuum-polarization…
Based on the precision experimental data of energy-level differences in hydrogenlike atoms, especially the 1S-2S transition of hydrogen and deuterium, the necessity of establishing a reduced Dirac equation (RDE) with reduced mass as the…