Novel strong interactions in the electroweak bosonic sector are expected to induce effective interactions between the Higgs doublet field and the electroweak gauge bosons which lead to anomalous W W Z and W W y vertices once the Higgs field acquires a vacuum expectation value. Using a linear realization of the Goldstone bosons, we consider a complete set of dimension-six operators which are SU(2)xU(l) gauge invariant and conserve C and P. This approach allows us to study effects of new physics which originates above 1 TeV and the Higgs boson mass dependence of the results can be investigated. Four of the dimension-six operators affect low energy and present CERN LEP experiments at the tree level. Another five influence neutral and charged current experiments at the one-loop level and three of these lead to anomalous W W Z and W W y vertices. Their loop contributions are at most logarithmically divergent, and these logarithmic divergences can be understood as renormalizations of the four operators which contribute at the tree level. Constraints on the remaining five operators can be obtained if one assumes the absence of cancellations between the tree level and one-loop contributions. The resulting bounds on anomalous triple gauge boson couplings are modest, which emphasizes the importance of direct measurements of the triple gauge boson vertices, e.g., in W + Wproduction at LEP 11. PACS number(s): 12.15. Cc, 12.15.Ji, 12.50.Lr, 14.80.Er
We update our standard model predictions for g − 2 of the muon and for the hadronic contributions to the running of the QED coupling, α (5) had M 2 Z . Particular emphasis is put on recent changes in the hadronic contributions from new data in the 2π channel and from the energy region just below 2 GeV. In particular, for the e + e − → π + π − contribution we include the recent 'radiative return' data from KLOE and BaBar. We also include the recent BaBar data on other exclusive channels. We make a detailed study of the effect of replacing the measurements of the inclusive cross section, σ (e + e − → hadrons), by the sum of the exclusive channels in the energy interval 1.43 < √ s < 2 GeV, which includes a QCD sum-rule analysis of this energy region. Our favoured prediction for the muon anomalous magnetic moment is (g − 2)/2 = (11 659 182.8 ± 4.9) × 10 −10 which is 3.3 σ below the present world-average measurement. We compare our g − 2 value with other recent calculations. Our prediction for the QED coupling, obtained via α (5) had M 2 Z = (276.26 ± 1.38) × 10 −4 , is α M 2 Z −1 = 128.944 ± 0.019.
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