Dilaton Physics from Asymptotic Freedom

TL;DR

This paper explores the emergence and properties of the dilaton in an asymptotically free three-dimensional Gross-Neveu-Yukawa theory, revealing universal aspects of its spectrum and mass in the context of spontaneous scale symmetry breaking.

Contribution

It provides a first-principles analysis of the dilaton in a strongly interacting, asymptotically free quantum field theory, including spectrum identification and universal mass expressions.

Findings

Identification of the dilaton in the spectrum via scalar two-point function

Universal expressions for the dilaton mass in terms of perturbations

Consistency with soft dilaton theorems

Abstract

The dilaton is investigated from first principles in an asymptotically free Gross-Neveu-Yukawa theory in three dimensions. In the limit of many fermion flavours, the theory features a finite line of strongly interacting fixed points with continuous quantum phase transitions and a massless Goldstone boson, the dilaton, following spontaneous scale symmetry breaking at its endpoint. Interestingly, we find that the emergence of a vacuum expectation value and a dilaton can be understood as a double-scaling limit. Exploiting the scalar two-point function, we identify the dilaton in the spectrum, compute its decay constant, and obtain universal expressions for the induced dilaton mass in terms of small perturbations. Consistency of findings with soft dilaton theorems is equally established. Implications for spontaneously broken conformal theories are indicated.