Related papers: Irreducible Three-Loop Vacuum-Polarization Correct…
We analytically compute quadratic mass corrections of order $\alpha_s^3 m_q^2/s$ to the absorptive part of the (non-diagonal) correlator of two axial vector currents. This allows us to find the correction of order $\alpha_s^3 m_q^2/M^2_W$…
A critical set of two-loop QED corrections to the $g$ factor of hydrogenlike ions is calculated without expansion in the nuclear binding field. These corrections are due to the polarization of the external magnetic field by the quantum…
The decay B_s -> mu^+ mu^- in the Standard Model is generated by the well-known W-box and Z-penguin diagrams that give rise to an effective quark-lepton operator Q_A at low energies. We compute QCD corrections of order alpha_s^2 to its…
We calculate the corrections of orders alpha^3, alpha^4 and alpha^5 to the Lamb shift of the 1S and 2S energy levels of muonic hydrogen (mu p) and muonic deuterium (mu d). The nuclear structure effects are taken into account in terms of the…
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…
A complete evaluation of the two-loop self-energy diagrams to all orders in Z\alpha is presented for the ground state of H-like ions with Z\ge 40.
I consider the so-called nuclear polarization correction to the 1S-levels in light to intermediate muonic atoms. An easy to use recipe to compute it is given. The calculation includes the effect of the nucleon polarization, i.e. the…
Relativistic third-order MBPT is applied to obtain energies of ions with two valence electrons in the no virtual-pair approximation (NVPA). A total of 302 third-order Goldstone diagrams are organized into 12 one-body and 23 two-body terms.…
Using perturbed relativistic coupled-cluster (PRCC) theory we compute the ground state electric dipole polarizability, $\alpha$, of doubly ionized alkaline earth metal ions $\rm{Mg}^{2+}$, $\rm{Ca}^{2+}$, $\rm{Sr}^{2+}$, $\rm{Ba}^{2+}$ and…
We derive quantum electrodynamics corrections to the fine structure in three-electron atomic systems at $m \alpha^6$ and $m \alpha^7 \ln \alpha$ orders and present their numerical evaluations for the Li atom and Be$^+$ ion.
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…
The next-to-leading order black-body radiation(BBR) shift to atomic energy-levels, namely $ (Z\alpha)^2\alpha T^2/m $ correction, was studied by using the nonrelativistic quantum electrodynamics(NRQED). We also estimate the one-loop…
We present new investigation of the Lamb shift (2P_{1/2}-2S_{1/2}) in muonic deuterium (mu d) atom using the three-dimensional quasipotential method in quantum electrodynamics. The vacuum polarization, nuclear structure and recoil effects…
We describe a simplified derivation for the relativistic corrections of order $\alpha^4$ for a bound system consisting of two spinless particles. We devote special attention to pionium, the bound system of two oppositely charged pions. The…
We report a calculation of all two-loop QED corrections with closed fermion loops for the n=1 and n=2 states of H-like ions and for a wide range of the nuclear charge numbers Z=1-100. The calculation is performed to all orders in the…
In order to reach a precision of $0.2\%$ on the hadronic vacuum polarization (HVP) contribution to the anomalous magnetic moment of the muon, $(g-2)_\mu$, such that the full Standard-Model prediction matches in precision the direct…
For muonic hydrogen, positronium, and ordinary hydrogen, we show that the existence of a relativistic two-body wave equation whose energy levels are physically accurate to order $(Z\alpha )^4$ (where $Z\alpha$ is the binding coupling…
We evaluate the three-loop massive vacuum bubble diagrams in terms of polylogarithms up to weight six. We also construct the basis of irrational constants being harmonic polylgarithms of arguments $e^{k i \pi/3}$.
Two-loop electroweak corrections to polarized Moller scattering are studied in two different schemes at low energies. We find the finite $Q^2$ corrections to be well under control. The hadronic and perturbative QCD corrections to the…
The nuclear size effect on the one-loop self energy and vacuum polarization is evaluated for the 1s, 2s, 3s, 2p_{1/2}, and 2p_{3/2} states of hydrogen-like ions. The calculation is performed to all orders in the binding nuclear strength…