A 125 GeV Scalar Boson and SU(N_{TC})\otimes SU(3)_{{}_{L}}\otimes U(1)_{{}_{X}} models

Abstract

We verify that SU(N)_{{}_{TC}}\otimes SU(3)_{{}_{L}}\otimes U(1)_{{}_{X}} models, where the gauge symmetry breaking is totally dynamical and promoted by the non-Abelian technicolor (TC) group and the strong Abelian interactions, are quite constrained by the LHC data. The theory contains a T quark self-energy involving the mixing between the neutral gauge bosons, which introduces the coupling between the light and heavy composite scalar bosons of the model. We determine the lightest scalar boson mass for these models from an effective action for composite operators, assuming details about the dynamics of the strong interaction theories. Comparing the value of this mass with the ATLAS and CMS observation of a new boson with a mass M_{\phi} \sim 125GeV and considering the lower bound determined by the LHC Collaborations on the heavy neutral gauge boson (Z^\prime) present in these models, we can establish constraints on the possible models. For example, if SU(N)_{{}_{TC}}\equiv SU(2)_{{}_{TC}}, with technifermions in the fundamental representation, the model barely survives the confrontation with the LHC data.