Related papers: Two-loop QED radiative corrections to the decay pi…
Pionic beta decay \pi^+ to \pi^0 e^+ \nu_e is analyzed in chiral perturbation theory with virtual photons and leptons. All electromagnetic corrections up to order e^2 p^2 are taken into account. Theoretical results are confronted with…
We consider quantum electrodynamics (QED) corrections to the fine splitting $E(2P_{3/2}) - E(2P_{1/2})$ in the Li atom. We derive complete formulas for the $m\,\alpha^6$ and $m\,\alpha^7\,\ln\alpha$ contributions and calculate them…
We compute the radiative corrections to the process of two-pion production in association with a hard photon in $e^+ e^-$ annihilation by taking into account the non-perturbative structure of the pion in the one-loop calculation. For this…
We compute mixed QCD-electroweak corrections to the fully-differential production of an on-shell $W$ boson. Decays of $W$ bosons to lepton pairs are included in the leading order approximation. The required two-loop virtual corrections are…
We analyse in detail the QED corrections to the total decay width and the moments of the electron energy spectrum of the inclusive semi-leptonic $B \to X_c e \nu$ decay. Our calculation includes short-distance electroweak corrections, the…
One-loop radiative corrections to the leptonic tensor in high energy bremsstrahlung on heavy nuclei are calculated. Virtual and real photon radiation is taken into account. Double bremsstrahlung is simulated by means of Monte Carlo.…
I discuss an application of numerical techniques for massive two-loop Feynman diagram evaluation to a phenomenologically very important rare decay process, B -> X_s l+l-. This process, currently being measured at B factories, has been…
We present the calculation of the virtual- and bremsstrahlung corrections of O(alpha_s) to the matrix elements <d l+ l-|O_i|b>. This is the missing piece in the NNLL results for various observables associated with the process B-> X_d l+ l-,…
In calculating electroweak radiative corrections at two-loop level, one encounters Feynman graphs with several different masses on the internal propagators and on the external legs, which lead to complicated scalar functions. We describe a…
We compute the two-loop mixed QCD-Electroweak corrections to $q \overline{q} \to H g$ and its crossed channels $q g \to H q$, $\overline{q} g \to H \overline{q}$, limiting ourselves to the contribution of light virtual quarks. We compute…
We present the results of the O(alpha_s) two-loop virtual corrections to the differential decay width dGamma(B -> X_s l+ l-)/ds, where s is the invariant mass squared of the lepton pair. Those contributions from gluon bremsstrahlung which…
We consider radiative corrections to false vacuum decay in a four-dimensional scalar field theory with cubic and quartic potential. Using planar thin wall approximation we were able to get analytical expression for the decay rate up to two…
Because of properties of QED, the bremsstrahlung corrections to decays of particles or resonances can be calculated, with a good precision, separately from other effects. Thanks to the widespread use of event records such calculations can…
We calculate the one-photon loop radiative corrections to the charged pion-pair production process $\pi^-\gamma\to\pi^+\pi^-\pi^-$. In the low-energy region this reaction is governed by the chiral pion-pion interaction. The pertinent set of…
We present for the first time the complete three-loop mixed electroweak-QCD ($\mathcal{O}(\alpha\alpha_s)$) corrections for the decay channel $H \to \gamma\gamma$, by implementing three different on-shell $\alpha$ schemes in computing the…
Radiating a photon from the initial state provides a useful tool for studying a range of low energy physics using a high-energy e+ e- accelerator. Accurate results require careful calculation of the first order virtual photon corrections.…
The simplest, algebraic quantum-electrodynamical corrections, due to the double-negative energy subspace and instantaneous interactions, are computed to the no-pair energy of two-spin-1/2-fermion systems. Numerical results are reported for…
We evaluate long-distance electromagnetic (QED) contributions to $\bar{B}{}^0 \to D^+ \tau^{-} \bar{\nu}_{\tau}$ and $B^- \to D^0 \tau^{-} \bar{\nu}_{\tau}$ relative to $\bar{B}{}^0 \to D^+ \mu^{-} \bar{\nu}_{\mu}$ and $B^- \to D^0 \mu^{-}…
We describe the impact of the full one-loop electroweak terms of O(alpha_s alpha_EM^3) entering the electron-positron into three-jet cross-section from sqrt(s)=M_Z to TeV scale energies. We include both factorisable and non-factorisable…
In this review some recent multi-loop results obtained in the framework of perturbative Quantum Chromodynamics (QCD) and Quantum Electrodynamics (QED) are discussed. After reviewing the most advanced techniques used for the computation of…