Symmetries for vector and axial-vector mesons

We discuss the possible symmetries of the effective lagrangian describing interacting pseudoscalar-, vector-, and axial-vector mesons. Specific choices of the parameters give rise to an [SU(2) ⊗ SU(2)]3 symmetry. This symmetry can be obtained either á la Georgi, with all states in the spectrum remaining massless, or in a new realization, implying decoupling of the pseudoscalar bosons from degenerate vector and axial-vector mesons. This second possibility, when minimally coupled with SU(2) ⊗ U(1) electroweak gauge vector bosons, seems particularly appealing. All deviations in the low-energy electroweak parameters are strongly suppressed, and the vector and axial-vector states turn out to be quite narrow. A nearby strong electroweak sector would then be conceivable and in principle it could be explored with relatively low energy accelerators.