  Due to the mass gap between the Standard Model and possible New Physics
states, electroweak effective approaches are appropriate. Although a linear
realization of the electroweak symmetry breaking with the Higgs forming a
doublet together with the Goldstone bosons of the EWSB is a first possibility
(SMEFT), we adopt the more general non-linear realization, where the Higgs is a
singlet with independent couplings (EWET, HEFT or EWChL). We present the
effective Lagrangian at low energies (the EWET, with only the SM fields) and at
high energies (the resonance theory, with also a set of resonances). Taking
into account the high scale of these resonances, their experimental searches
seem to be more accessible by considering their imprints at low-energies, i.e.,
their imprints in the Low Energy Constants (LECs) of the EWET at energies lower
than the resonance masses. We give some examples of these phenomenological
connections.
