  In the light of the mass gap between Standard Model (SM) states and possible
new particles, effective field theories are a suitable approach. We take on the
non-linear realization of the electroweak symmetry breaking: the electroweak
effective theory (EWET), also known as Higgs effective field theory (HEFT) or
electroweak chiral Lagrangian (EWChL). At higher scales we consider a resonance
electroweak Lagrangian, coupling SM fields to resonances. Integrating out these
resonances and assuming a well-behaved high-energy behavior, some of the
bosonic low-energy constants are determined or constrained in terms of
resonance masses. Present experimental bounds on these low-energy constants
allow us to push the resonance mass scale to the TeV range, $M_R \geq 2\,$TeV,
in good agreement with previous estimations.
