Gauge boson couplings at LEP

A review is given of the measurements of triple and quartic couplings among the electroweak gauge bosons performed at LEP by the four experiments ALEPH, DELPHI, L3 and OPAL. Emphasis is placed on recently published results and on combinations of results performed by the LEP electroweak gauge-couplings group. All measurements presented are consistent with the Standard Model expectations.Comment: 6 pages, 7 figures. To be published in the proceedings of the BEACH04 conference, Chicago, June 27-July 3 200

Higgs Decay to Top Quarks at Hadron Colliders

Higgs bosons which decay principally to top quarks, such as in the minimal supersymmetric model, produce a peak-dip structure in the $gg\to t\bar t$ invariant-mass spectrum. This structure is potentially observable at the CERN Large Hadron Collider. (see BNL theory home page http://penguin.phy.bnl.gov/bnl.html for recent preprints)Comment: CPP-94-18, BNL-60339, ILL-(TH)-94-

Electroweak Physics, Experimental Aspects

Collider measurements on electroweak physics are summarised. Although the precision on some observables is very high, no deviation from the Standard Model of electroweak interactions is observed. The data allow to set stringent limits on some models for new physics.Comment: Plenary Talk at the UK Phenomenology Workshop on Collider Physics, Durham, 199

Large Tree Level CP Violation in e+e−→ttˉH0e^+e^-\to t\bar{t}H^0 in The Two Higgs Doublet Model

We find a large CP violation effect within the Two-Higgs-Doublet-Model for the reaction $e^+e^-\to t\bar{t}H^0$ at future linear colliders. The CP-asymmetry arises already at the tree level as a result of interference between diagrams with $H^0$ emission from $t$ (and $\bar{t}$) and its emission from a $Z^0$ and can be about 10--20\%. In the best case one needs a few hundred $t\bar{t}H^0$ events to observe CP violation at the 3$\sigma$ level.Comment: UU encoded tar compressed tex file with postscript figure