Low energy strong electroweak sector with decoupling

We discuss possible symmetries of effective theories describing spinless and spin-1 bosons, mainly to concentrate on an intriguing phenomenological possibility: that of a hardly noticeable strong electroweak sector al relatively low energies. Specifically, a model with both vector and axial vector strong interacting bosons may possess a discrete symmetry imposing degeneracy of the two sets of bosons (degenerate BESS model). in such, a case its effects at low energies become almost invisible and the mode: easily passes al::ow energy precision tests. The reason. lies essentially in the fact that the mode: automatically satisfies decoupling, contrary to models with only vectors. For large mass of the degenerate spin-one bosons the model becomes identical at the classical level to the standard model taken, in the limit of infinite Higgs boson mass. For these reasons we have thought ii worthwhile to fully develop the model, together with its possible generalizations, and to study the expected phenomenology. For instance, just because of its invisibility at low energy, it is conceivable that degenerate BESS has low mass spin-one states and giver, quite visible signals a: existing a; forthcoming accelerators.