Conformal Dynamics for TeV Physics and Cosmology

TL;DR

The paper surveys the phase structure of non-Abelian gauge theories with fermionic matter in diverse representations and connects this to conformal dynamics, unparticle physics, and cosmology. It introduces an all-orders beta function for chiral gauge theories and presents new phase-diagram results for generalized Bars-Yankielowicz and Georgi-Glashow chiral theories, enabling a unified treatment of chiral and non-chiral fermions. It discusses minimal walking models as conformal extensions relevant to dynamical electroweak symmetry breaking and analyzes the electroweak phase transition within these frameworks. By embedding unparticle ideas into a composite dynamics setting, the work proposes ETU constructions that aim to address naturalness and the origin of mass via strongly coupled dynamics.

Abstract

We introduce the topic of dynamical breaking of the electroweak symmetry and its link to unparticle physics and cosmology. The knowledge of the phase diagram of strongly coupled theories plays a fundamental role when trying to construct viable extensions of the standard model (SM). Therefore we present the state-of-the-art of the phase diagram for SU, Sp and SO gauge theories with fermionic matter transforming according to arbitrary representations of the underlying gauge group. We summarize several analytic methods used recently to acquire information about these gauge theories. We also provide new results for the phase diagram of the generalized Bars-Yankielowicz and Georgi-Glashow chiral gauge theories. These theories have been used for constructing grand unified models and have been the template for models of extended technicolor interactions. To gain information on the phase diagram of chiral gauge theories we will introduce a novel all orders beta function for chiral gauge theories. This permits the first unified study of all non-supersymmetric gauge theories with fermionic matter representation both chiral and non-chiral. To the best of our knowledge the phase diagram of these complex models appears here for the first time. We will introduce recent extensions of the SM featuring minimal conformal gauge theories known as minimal walking models. Finally we will discuss the electroweak phase transition at nonzero temperature for models of dynamical electroweak symmetry breaking.

Figures (12)

• Figure 1: Cartoon representing the various forces of nature. At very high energies one may imagine that all the low-energy forces unify in a single force.
• Figure 2: Postage stamp representing all of the elementary particles which constitute the SM. The forces are mandated with the $SU(3)\times SU(2) \times U(1)$ gauge group.
• Figure 3: The SM can be viewed as a low-energy theory valid up to a high energy scale $\Lambda$.
• Figure 4: Values of the Higgs mass extracted from different electroweak observables. The average is shown as a green band.
• Figure 5: The 1-$\sigma$ range of the electroweak parameters $S$ and $T$ determined from different observables. The ellipsis shows the 68% probability from combined data. The yellow area gives the SM prediction with $m_t$ and $m_H$ varied as shown.