相关论文: Complete 2-loop quantum electrodynamic contributio…
We present a new independent evaluation of the hadronic and QCD contributions to the QED running coupling \alpha(M_Z) and to the muonium hyperfine splitting \nu. We obtain: \Delta\alpha_{had}=2770(17)10^{-5} and \Delta\nu_{had}=232.5(2.5)…
I review recent evaluations of the hadronic contributions to the muon anomalous magnetic moment (g-2)_mu and to the effective fine structure constant alpha (M_Z). A new estimate for the hadronic shift delta_alpha hadronic = 0.027782 +/-…
We have reevaluated the hadronic contribution to the anomalous magnetic moment of the muon (g-2) and to the running of the QED fine structure constant alpha(s) at s=M_Z**2. We incorporated new data from hadronic tau decays, recently…
I present the leading 3-loop contributions to the Fermi decay constant in the Standard Model, using the tadpole-free pure $\overline{\rm{MS}}$ scheme. The calculation is exact in the limit in which the QCD coupling, the top-quark Yukawa…
The details of the recent calculation of the two-loop bosonic corrections to the muon lifetime in the Standard Model are presented. The matching on the Fermi theory is discussed. Renormalisation in the on-shell and in the MS scheme is…
Preliminary numerical results of calculating the 5-loop QED contributions to the electron (and muon) anomalous magnetic moment are presented. The results include the total contribution of the 5-loop Feynman diagrams without lepton loops and…
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…
We present the NNLO QCD virtual corrections for qurak-antiquark -> gluon photon, quark-antiquark -> photon photon and the NNLO QED virtual corrections for electron positron -> photon photon and all processes related by crossing symmetry. We…
We study the ${\text{2HDM}}$ contribution to the muon anomalous magnetic moment $a_\mu$ and present the complete two-loop result, particularly for the bosonic contribution. We focus on the Aligned ${\text{2HDM}}$, which has general Yukawa…
This work presents a complete re-evaluation of the hadronic vacuum polarisation contributions to the anomalous magnetic moment of the muon, $a_{\mu}^{\rm had, \, VP}$ and the hadronic contributions to the effective QED coupling at the mass…
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…
For the first time the experiments ALEPH, DELPHI, L3 and OPAL have presented preliminary results for fermion-pair and photon-pair production in e+e- collisions on the full LEP2 data set. The details of the experimental measurements and…
A review of the calculation of the two loop bosonic corrections to $\Delta r$ is presented. Factorization and matching onto the Fermi model are discussed. An approximate formula, describing the quantity over the interesting range of Higgs…
We use recently evaluated radiative and nonperturbative corrections to production of heavy quarks by a vector current to give very precise theoretical calculations of the high energy ($t^{1/2}\geq \sqrt{2}$ GeV) imaginary part of the photon…
We present an introduction to the MuLAN and MuCAP experiments at PSI, which aim at high precision determinations of two fundamental Weak Interactions parameters: the Fermi constant $G_{F}$ and the induced pseudoscalar form factor $g_{p}$,…
We calculate (g-2) of the muon and the QED coupling alpha(M_Z^2), by improving the determination of the hadronic vacuum polarization contributions and their uncertainties. We include the recently re-analysed CMD-2 data on e^+e^- -> pi^+…
Recently, first results were presented for two-loop corrections to the muon (g-2) from fermion/sfermion loops in the MSSM. These corrections were shown to be generally large and even logarithmically enhanced for heavy sfermions. Here, full…
We reevaluate the hadronic contributions to the muon magnetic anomaly, and to the running of the electromagnetic coupling constant at the Z-boson mass. We include new pi+pi- cross-section data from KLOE, all available multi-hadron data from…
The MuLan experiment will measure the lifetime of the positive muon to 1ppm. Within the Standard Model framework, this will permit a determination of the Fermi Constant to 0.5ppm. I present an update on our progress and achievements to…
The first results from the Fermilab E989 experiment have confirmed the long-standing tension between the experimental determination of the muon anomalous magnetic moment $a_\mu=(g_\mu-2)/2$ and its SM determination using the dispersive…