A new dynamics of electroweak symmetry breaking with classically scale invariance

TL;DR

This paper introduces a novel electroweak symmetry breaking mechanism within a classically scale-invariant standard model, utilizing strong coupling dynamics and a bosonic seesaw to generate the Higgs mass and avoid massless Goldstone bosons.

Contribution

It presents a new model where electroweak symmetry breaking arises from fermion condensates and strong dynamics, incorporating a pseudo-scalar singlet to address Goldstone bosons, and realizes the flatland scenario with dimensional transmutation.

Findings

Mass spectra and decay rates of pseudo-Nambu-Goldstone bosons are consistent with cosmological constraints.

The model achieves electroweak symmetry breaking via strong coupling and bosonic seesaw mechanisms.

The energy dependence of couplings supports the flatland scenario with a metastable vacuum.

Abstract

We propose a new dynamics of the electroweak symmetry breaking in a classically scale invariant version of the standard model. The scale invariance is broken by the condensations of additional fermions under a strong coupling dynamics. The electroweak symmetry breaking is triggered by negative mass squared of the elementary Higgs doublet, which is dynamically generated through the bosonic seesaw mechanism. We introduce a real pseudo-scalar singlet field interacting with additional fermions and Higgs doublet in order to avoid massless Nambu-Goldstone bosons from the chiral symmetry breaking in a strong coupling sector. We investigate the mass spectra and decay rates of these pseudo-Nambu-Goldstone bosons, and show they can decay fast enough without cosmological problems. We further evaluate the energy dependences of the couplings between elementary fields perturbatively, and find that our model is the first one which realizes the flatland scenario with the dimensional transmutation by the strong coupling dynamics. Similarly to the conventional flatland model with Coleman-Weinberg mechanism, the electroweak vacuum in our model is meta-stable.