Electroweak effective theory and beyond Standard Model resonances

We consider a non-linear realization of the electroweak symmetry-breaking pattern $SU(2{)}_L\times SU(2{)}_R\mathrm{/}SU(2{)}_{L+R}$ to construct a low-energy effective theory, later extended by the inclusion of heavy new-physics resonances. After assuming appropriate high-energy constraints given by Weinberg sum-rules and the asymptotic behaviour of form-factors, we obtain relations between resonance masses and some low-energy effective couplings. These predictions are compared with current experimental data and some resonance mass bounds are inferred.