Dynamical Stabilization of the Fermi Scale: Phase Diagram of Strongly Coupled Theories for (Minimal) Walking Technicolor and Unparticles
Francesco Sannino
TL;DR
This work surveys how strongly coupled gauge theories can dynamically stabilize the Fermi scale and what phase structures arise as a function of color, flavor, and representation. It develops and tests an all‑orders beta function to bound conformal windows, connects IR fixed points to walking behavior, and applies these ideas to construct and constrain Minimal Walking Technicolor and its extensions. The text integrates unparticle construction, EW precision constraints, dark matter considerations, and unification prospects, showing that walking dynamics can alleviate FCNCs while enabling viable spectra with potentially light vector/axial resonances. It also explores how technicolor scenarios can be embedded into grand unification and how adjoint matter can improve unification and proton decay constraints, offering a coherent framework for phenomenology at colliders and in cosmology.
Abstract
We summarize basic features associated to dynamical breaking of the electroweak symmetry. The knowledge of the phase diagram of strongly coupled theories as function of the number of colors, flavors and matter representation plays a fundamental role when trying to construct viable extensions of the standard model (SM). Therefore we will report on the status of the phase diagram for SU(N) gauge theories with fermionic matter transforming according to arbitrary representations of the underlying gauge group. We will discuss how the phase diagram can be used to construct unparticle models. We will then review Minimal Walking Technicolor (MWT) and other extensions, such as partially gauged and split technicolor. MWT is a sufficiently general, symmetry wise, model to be considered as a benchmark for any model aiming at breaking the electroweak symmetry dynamically. The unification of the standard model gauge couplings will be revisited within technicolor extensions of the SM. A number of appendices are added to review some basic methods and to provide useful details. In one of the appendices we will show how to gain information on the spectrum of strongly coupled theories relevant for new extensions of the SM by introducing and using alternative large N limits.