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

The purely electroweak process qq → qqZ (via t-channel γ/Z or W exchange) provides a copious and fairly clean source of color-singlet exchange events in pp collisions at the LHC. A judicious choice of phase-space region allows the suppression of QCD backgrounds to the level of the signal. The color-singletexchange signal can be distinguished from QCD backgrounds by the radiation patterns of additional minijets in individual events. A rapidity-gap trigger at the minijet level substantially enhances the signal versus the background.Analogous features of weak boson scattering events make Z + 2-jet events at the LHC an ideal laboratory for investigation of the soft-jet activity expected in weak-boson scattering events.

It is possible to place constraints on non-standard-model gauge-boson self-couplings and other new physics by studying their one-loop contributions to precisely measured observables. We extend previous analyses which constrain such nonstandard couplings, and we present the results in a compact and transparent form. Particular attention is given to comparing results for the light-Higgs scenario, where nonstandard effects are parametrized by an effective Lagrangian with a linear realization of the electroweak symmetry-breaking sector, and the heavy-Higgs or strongly interacting scenario, described by the electroweak chiral Lagrangian. The constraints on nonstandard gauge-boson self-couplings which are obtained from a global analysis of lowenergy data and CERN LEP or SLC measurements on the Z pole are updated and improved from previous studies. ͓S0556-2821͑97͒01523-3͔

No abstract

A non-standard symmetry breaking sector may lead to derivative couplings of the Higgs boson and thereby to anomalous interactions with the electroweak gauge bosons. In the framework of gauge-invariant effective Lagrangians the resulting changes in Higgs boson production and decay mechanisms are related to anomalous triple vector boson couplings. Using low energy constraints on the dimension-six operators in the effective Lagrangian, we discuss the size of deviations from SM predictions which may be expected in Higgs boson production and decay rates. Large enhancements are allowed e.g. in the Z → Hγ and H → γγ partial decay widths, leading to Z → γγγ events at LEP.