Conformal Phase Transition in Gauge Theories

TL;DR

This paper introduces and analyzes the conformal phase transition in gauge theories, highlighting its unique features such as an abrupt change in excitation spectrum despite a continuous transition, with implications for QCD and electroweak models.

Contribution

It develops a detailed theoretical framework for the conformal phase transition, connecting it with effective actions and partially conserved currents in gauge theories.

Findings

Abrupt change in light excitation spectrum at the critical point

Continuous phase transition with distinct spectral features

Applications to QCD and electroweak symmetry breaking models

Abstract

The conception of the conformal phase transiton (CPT), which is relevant for the description of non-perturbative dynamics in gauge theories, is introduced and elaborated. The main features of such a phase transition are established. In particular, it is shown that in the CPT there is an abrupt change of the spectrum of light excitations at the critical point, though the phase transition is continuous. The structure of the effective action describing the CPT is elaborated and its connection with the dynamics of the partially conserved dilatation current is pointed out. The applications of these results to QCD, models of dynamical electroweak symmetry breaking, and to the description of the phase diagram in (3+1)-dimensional $ SU(N_c)$ gauge theories are considered.