[Paper Review] Strong Coupling Electroweak Symmetry Breaking

T. Barklow, Gustavo Burdman+8 more|arXiv (Cornell University)|Apr 3, 1997

Cosmology and Gravitation Theories2 references3 citations

TL;DR

This paper reviews strong dynamics as a mechanism for electroweak symmetry breaking at the TeV scale, proposing that new strong interactions generate the Higgs sector via composite states. It emphasizes direct detection of these dynamics through high-energy vector boson scattering, with key predictions for LHC and future colliders.

ABSTRACT

We review models of electroweak symmetry breaking due to new strong interactions at the TeV energy scale and discuss the prospects for their experimental tests. We emphasize the direct observation of the new interactions through high-energy scattering of vector bosons. We also discuss indirect probes of the new interactions and exotic particles predicted by specific theoretical models. [Working group summary report from the Snowmass `96 summer study, to appear in the proceedings.]

Motivation & Objective

• To explore electroweak symmetry breaking via new strong interactions at the TeV scale, alternative to the Standard Model Higgs.
• To identify observable signatures of strong dynamics in high-energy scattering processes, particularly vector boson scattering.
• To assess the feasibility of detecting composite Higgs-like states and exotic resonances at future colliders.
• To provide a phenomenological framework for testing strong dynamics models through direct and indirect experimental probes.
• To summarize the state of the field following the Snowmass 1996 workshop, guiding future experimental and theoretical efforts.

Proposed method

• Analyzes effective field theories with strong dynamics near the TeV scale to describe new physics beyond the Standard Model.
• Uses unitarity constraints and partial wave amplitudes to identify the energy scale where new physics must emerge.
• Focuses on the scattering of longitudinal vector bosons (W and Z) as a primary probe of strong dynamics.
• Applies constraints from precision electroweak data to narrow viable models of strong symmetry breaking.
• Evaluates the potential for discovering new resonances such as techni-rho states and composite Higgs particles.
• Compares predictions of strong dynamics models with those of the minimal Higgs mechanism, highlighting distinguishing signatures.

Experimental results

Research questions

• RQ1 What are the key experimental signatures of strong dynamics in electroweak symmetry breaking?
• RQ2 How can high-energy vector boson scattering processes reveal the presence of new strong interactions?
• RQ3 What constraints do precision electroweak measurements impose on strongly-coupled models?
• RQ4 What are the predicted properties and decay modes of composite Higgs and exotic resonances?
• RQ5 How do strong dynamics models compare with the Standard Model in terms of unitarity and naturalness?

Key findings

• Strong dynamics at the TeV scale can generate the Higgs sector through the formation of composite states, avoiding fundamental Higgs bosons.
• Direct observation of new physics is most promising through high-energy scattering of longitudinal W and Z bosons.
• Unitarity violation in vector boson scattering signals the need for new physics around 1–2 TeV, consistent with strong dynamics.
• Models predict the existence of heavy spin-1 resonances (e.g., techni-rho states) that could be detected at the LHC or future colliders.
• Precision electroweak data constrain the scale of new physics, favoring models with strong dynamics near 1 TeV.
• The paper identifies specific collider signatures—such as enhanced diboson production and resonant states—that distinguish strong dynamics from the Standard Model.