Dynamical Origin of the Electroweak Scale and the 125 GeV Scalar

TL;DR

This paper proposes a dynamical mechanism for electroweak symmetry breaking where a composite scalar, originating from new strong interactions, can naturally have a mass of 125 GeV, consistent with experimental observations, and predicts additional heavy resonances.

Contribution

It introduces a model where the electroweak scale and scalar mass arise from new strong dynamics and four-fermion interactions, explaining the light scalar and predicting heavy resonances.

Findings

Scalar mass can be reduced to 125 GeV from TeV-scale origin.

Model compatible with current LHC measurements.

Predicts new resonances at a few TeV accessible in future experiments.

Abstract

We consider a fully dynamical origin for the masses of weak gauge bosons and heavy quarks of the Standard Model. Electroweak symmetry breaking and the gauge boson masses arise from new strong dynamics, which leads to the appearance of a composite scalar in the spectrum of excitations. In order to generate mass for the Standard Model fermions, we consider extended gauge dynamics, effectively represented by four fermion interactions at presently accessible energies. By systematically treating these interactions, we show that they lead to a large reduction of the mass of the scalar resonance. Therefore, interpreting the scalar as the recently observed 125 GeV state, implies that the mass originating solely from new strong dynamics can be much heavier, {\em {\em i.e.}} of the order of 1 TeV. In addition to reducing the mass of the scalar resonance, we show that the four-fermion interactions allow for contributions to the oblique corrections in agreement with the experimental constraints. The couplings of the scalar resonance with the Standard Model gauge bosons and fermions are evaluated, and found to be compatible with the current LHC results. Additional new resonances are expected to be heavy, with masses of the order of a few TeVs, and hence accessible in future experiments.