Hidden SU(2)V boson, electroweak observables and the top mass bounds

Deviations from standard model in parameters measured at LEP and other experiments are discussed, resulting from an additional SU(2)V boson with specific properties. This new boson may be expected typically as a vector resonance in no-Higgs scenarios (e.g. strongly interacting Higgs sector, or composite W models), but also in more conventional (renormalizable) SU(2)V extensions of the electroweak theory. It is also argued that the deviations might conspirate to allow a substantially higher top mass than the standard one, due to the peculiar SU(2) global structure and breaking within such model. The possible relevance of these features to some recent models of dynamical electroweak breaking via heavy top condensation is briefly motivated. (author) 21 refs