  As a first step towards the construction of a general electroweak effective
Lagrangian incorporating heavy states, we present here a simplified version
where only vector and axial-vector spin-1 triplets are involved. We adopt an
effective field theory formalism, implementing the electroweak chiral symmetry
breaking SU(2)L x SU(2)R -> SU(2)L+R, which couples the heavy states to the SM
fields. At low energies, the heavy degrees of freedom are integrated out from
the action and their effects are hidden in the low-energy couplings of the
Electroweak Effective Theory, which can be tested experimentally.
Short-distance constraints are also implemented, requiring a proper behaviour
in the high-energy regime. We analyze the phenomenological constraints from the
oblique parameters S and T , at the next- to-leading order. Our results show
that present data allow for strongly-coupled scenarios with massive bosons
above the TeV scale.
