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

TL;DR

This paper investigates SU(N) technicolor models with extended gauge symmetries, analyzing their scalar boson mass predictions in light of LHC data, and constrains their viability based on experimental observations of a 125 GeV boson.

Contribution

It provides a detailed analysis of the scalar boson mass in extended technicolor models using an effective action approach, linking theoretical predictions with LHC experimental constraints.

Findings

The predicted scalar boson mass aligns with the observed 125 GeV for certain model parameters.

Models with SU(2) technicolor and fundamental technifermions are barely compatible with LHC data.

Constraints from Z' boson mass bounds significantly restrict the model parameter space.

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.