相关论文: Probing QCD Corrections to QED Effects Through Opt…
Corrections $\sim \alpha^2 $ to the positronium decay rate, induced by one--loop vacuum polarization diagram, are calculated. Their relative values are $0.4468(3)(\alpha/\pi)^2$ for para- and $0.960(3)(\alpha/\pi)^2$ for orthopositronium.
We compute the leading QED corrections to the hadronic vacuum polarization (HVP) of the photon, relevant for the determination of leptonic anomalous magnetic moments, $a_\ell$. We work in the electroquenched approximation and use dynamical…
QED corrections to the $g$ factor of Li-like and B-like ions in a wide range of nuclear charges are presented. Many-electron contributions as well as radiative effects on the one-loop level are calculated. Contributions resulting from the…
We present a first-principles lattice QCD+QED calculation at physical pion mass of the leading-order hadronic vacuum polarization contribution to the muon anomalous magnetic moment. The total contribution of up, down, strange, and charm…
We demonstrate that the dispersive computation of the threshold enhancements to heavy quark vacuum polarizations is unstable. Because of the slow convergence of the dispersion relations the result critically depends on the intermediate…
The QED vacuum polarization in external monochromatic plane-wave electromagnetic fields is calculated with spatial and temporal variations of the external fields being taken into account. We develop a perturbation theory to calculate the…
The differential cross section for elastic scattering of protons on electrons at rest is calculated taking into account the QED radiative corrections to the leptonic part of interaction. These model-independent radiative corrections arise…
The QED vacuum polarization function is calculated to O(alpha^2) (next-to-leading order) accuracy in the threshold regime by using the concept of effective field theories to resum diagrams with the instantaneous Coulomb exchange of…
The rotation of the polarization vector for light propagating perpendicular to an external constant external magnetic field $B$, is calculated in quantum vacuum, where it leads to different photon eigenmodes of the magnetized photon…
Relative order \alpha(Z\alpha)^3 shift of the energy levels induced by the vacuum polarization is reexamined for a bound system of two particles with masses m and M. Recent results for hydrogen and for positronium are shown to contain an…
A statistical analysis of the elastic unpolarized electron proton scattering data shows that, at large momentum transfer, the size and the $\epsilon$ dependence of the radiative corrections, as traditionally calculated and applied, may…
We study the effect of vacuum polarization in nuclear reactions of astrophysical interest. This effect has the opposite sign compared to the screening by the atomic electrons. It is shown that vacuum polarization further increases the…
Theoretical predictions for Bhabha scattering at the two-loop level require the inclusion of hadronic vacuum polarization in the photon propagator. We present predictions for the contributions from reducible amplitudes which are…
We re-evaluate the matrix element for the proton-proton reaction which is important for stellar-evolution calculations and for the solar-neutrino problem. We self-consistently determine the effect of vacuum polarization on the matrix…
The photon emission by an ultrarelativistic charged particle in extremely strong magnetic field is analyzed, with vacuum polarization and photon recoil taken into account. The vacuum polarization is treated phenomenologically via refractive…
We review recent results in lattice QCD from numerical simulations that allow for a much more realistic QCD vacuum than has been possible before. Comparison with experiment for a variety of hadronic quantities gives agreement to within…
We determine the contribution to the anomalous magnetic moment of the muon from the $\alpha^2_{\mathrm{QED}}$ hadronic vacuum polarization diagram using full lattice QCD and including $u/d$ quarks with physical masses for the first time. We…
The QCD coupling appears in the perturbative expansion of the current-current two-point (vacuum polarization) function. Any lattice calculation of vacuum polarization is plagued by several competing non-perturbative effects at small momenta…
Isospin-breaking corrections to the hadron vacuum polarization component of the anomalous magnetic moment of the muon are needed to ensure the theoretical precision of $g_\mu -2$ is below the experimental precision. We describe the status…
This paper studies the impact of vacuum polarization on light propagation in the background of a distorted, deformed compact object. Focusing on a spacetime containing two quadrupole parameters associated with the central object and…