Top Quark Seesaw Theory of Electroweak Symmetry Breaking

TL;DR

The paper proposes a dynamical mechanism for electroweak symmetry breaking where the left-handed top quark condenses with a new vectorlike $\chi$ quark via topcolor-like interactions, creating a composite Higgs with $v/\sqrt{2} \approx 175$ GeV and a naturally suppressed top mass through a seesaw mixing. A detailed effective potential framework (including general four-fermion interactions and auxiliary scalar fields) analyzes vacuum alignment, scalar spectra, and the conditions under which a light neutral Higgs $h^0$ can emerge, even as many other scalars are heavy. The authors present higher-energy constructions (moose models) where topcolor breaking is dynamical and flavor structure arises from extended interactions, showing the feasibility of forming realistic fermion masses while constraining custodial symmetry violations. Overall, the work offers a viable dynamical alternative to a fundamental Higgs, with concrete predictions for the Higgs sector and clear directions for embedding flavor and testing at high energies.

Abstract

We study electroweak symmetry breaking involving the seesaw mechanism of quark condensation. These models produce a composite Higgs boson involving the left-handed top quark, yet the top mass arises naturally at the observed scale. We describe a schematic model which illustrates the general dynamical ideas. We also consider a generic low-energy effective theory which includes several composite scalars, and we use the effective potential formalism to compute their spectrum. We develop a more detailed model in which certain features of the schematic model are replaced by additional dynamics.

Figures (2)

• Figure 1: The "moose" model of dynamical topcolor symmetry breaking.
• Figure 2: Coupled gap equations ($A,B = t, \chi$).