Related papers: Three-Loop Contributions to Hyperfine Splitting: M…
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…
This paper reports the tenth-order QED contribution to the lepton g-2 from the gauge-invariant set, called Set III(c), which consists of 390 Feynman vertex diagrams containing an internal fourth-order light-by-light-scattering subdiagram.…
This paper reports the tenth-order QED contribution to lepton g-2 from diagrams of three gauge-invariant sets VI(d), VI(g), and VI(h), which are obtained by including various fourth-order radiative corrections to the sixth-order g-2…
The contribution of hadronic scattering of light-by-light to the hyperfine structure of muonium is calculated using experimental data on the transition form factors of two photons into a hadron. The amplitudes of interaction between a muon…
This paper contains some new results on the hadronic light-by-light contribution (HLbL) to the muon $g-2$. The first part argues that we can expect large effects from disconnected diagrams in present and future calculations by lattice QCD…
We discuss, within the framework of the Standard Model, the calculation of the two-loop electroweak contributions to the anomalous magnetic moment of the muon involving triangle fermionic loops of leptons and quarks. Because of the large…
We report about recent results obtained for the muon anomalous magnetic moment. Three-loop kernel functions have been computed to obtain the next-to-next-to-leading-order hadronic vacuum polarization contributions. The numerical result,…
We present a determination of a new class of three-loop Feynman diagrams describing heavy-to-light transitions. We apply it to find the O(alpha_s^2) corrections to the top quark decay t -> bW and to the distribution of lepton invariant mass…
We present an analytic calculation of electron and tau O(alpha^3) loop effects on the muon anomalous magnetic moment. Computation of such three-loop diagrams with three mass scales is possible using asymptotic and eikonal expansions. An…
We present analytic results for three-loop fermionic corrections to the heavy-light form factors in perturbative quantum chromodynamics. Specifically, we present all light quark contributions and contributions from two heavy quark loops. We…
In Refs. [1,2] we provided a complete dispersive evaluation of the hadronic light-by-light (HLbL) contribution to the anomalous magnetic moment of the muon. While the evaluation strategy was developed for the kinematic situation determined…
Hadronic contributions dominate the uncertainty of the standard model prediction for the anomalous magnetic moment of the muon. In this work, we describe an ongoing lattice calculation of the hadronic light-by-light contribution, performed…
We revisit the contributions of order $\alpha^2(Z\alpha)^5m$ and $\alpha^2(Z\alpha)E_F$, respectively, to the Lamb shift and to the hyperfine splitting from mixed self-energy-vacuum-polarization diagrams, involving fermionic loop. We use…
We present the first calculation of the complete set of NNLO QED corrections for muon-electron scattering. This includes leptonic, non-perturbative hadronic, and photonic contributions. All fermionic corrections as well as the photonic…
I summarize our self-contained determinations of the lowest order hadronic contributions to the anomalous magnetic moments a_{\mu,\tau} of the muon and tau leptons, the running QED coupling \alpha(M_Z) and the muonium hyperfine splitting…
Following updates in the compilation of $e^+e^-\rightarrow{\rm hadrons}$ data, this work presents re-evaluations of the hadronic vacuum polarisation contributions to the anomalous magnetic moment of the electron ($a_e$), muon ($a_\mu$) and…
The hadronic light-by-light contribution to a_{mu}, the anomalous magnetic moment of the muon, is discussed from the point of view of an effective low-energy theory. As an application, the coefficient of the leading logarithm arising from…
Hard spin-independent three-loop radiative contributions to energy levels in positronium generated by the two-photon-exchange diagrams with one-loop radiative insertions in the fermion lines and exchanged photons are calculated. This is a…
In this contribution we present recent four-loop results for the muon anomalous magnetic moment based on analytic methods. In particular, fermionic corrections involving two or more closed electron loops or at least one tau lepton loop are…
We give a short overview of the theory of the muon anomalous magnetic moment with emphasis on the hadronic light-by-light and the pion loop contribution. We explain the difference between the hidden local symmetry and full VMD pion loop and…