Delgado López, RafaelDobado González, AntonioLlanes Estrada, Felipe José2023-06-172023-06-172017-03-311434-604410.1140/epjc/s10052-017-4768-yhttps://hdl.handle.net/20.500.14352/18243© The Author(s) 2017. We thank for useful conversation and suggestions J.J. Sanz-Cillero, D. Espriu, and M.J. Herrero. Work supported by Spanish MINECO Grants FPA2011-27853-C02-01, FPA2014-53375-C2-1- P and BES-2012-056054 (RLD).We define and calculate helicity partial-wave amplitudes for processes linking the Electroweak Symmetry Breaking Sector (EWSBS) to γ γ , employing (to NLO) the Higgs-EFT (HEFT) extension of the Standard Model and the Equivalence Theorem, while neglecting all particle masses. The resulting amplitudes can be useful in the energy regime (500 GeV−3 TeV). We also deal with their unitarization so that resonances of the EWSBS can simultaneously be described in the γ γ initial or final states. Our resulting amplitudes satisfy unitarity, perturbatively in α, but for all s values. In this way we improve on the HEFT that fails as interactions become stronger with growing s and we provide a natural framework for the decay of dynamically generated resonances into W W, Z Z and γ γ pairs.engAtribución 3.0 Españahttps://creativecommons.org/licenses/by/3.0/es/journal articlehttp://dx.doi.org/10.1140/epjc/s10052-017-4768-yhttps://rd.springer.comopen access53Chiral perturbation-theorySymmetry-breaking sectorStrongly interacting WSHiggs-BosonStandard modelElectroweak parametersTechnicolor theoriesEquivalence theoremMassCollisions.Física-Modelos matemáticos