A glimpse of heavy scales through the electroweak resonance theory

The apparent absence of new heavy states at the LHC below the TeV scale points that there is a gap in the electroweak energy spectrum. This scenario is conveniently described through the electroweak effective theory, an effective description that contains the Standard Model fields and symmetries. A generic non-linear realization of the electroweak symmetry breaking pattern $SU(2)_L \otimes SU(2)_R \to SU(2)_{L+R}$ with a singlet Higgs is adopted, with no assumption about how it couples to the Standard Model. To seek for heavy particles, we formulate the electroweak resonance theory as the most general high-energy Lagrangian including both fermionic and $J^P = 0^\pm,\, 1^\pm$ bosonic heavy states, where all the resonances can form n-plets under the electroweak and the color group. An extended analysis of the imprints that the heavy states leave on the low-energy theory is performed, with an special emphasis on spin-1 fields and their formalism implementation. We study the phenomenology of the $P$ even purely bosonic sector of the resonance theory, where the low-energy predictions are refined with the assumption of very reasonable ultraviolet constraints.