Gravitational coupling of QED and QCD: 3- and 4- point functions in momentum space

TL;DR

This paper investigates the effects of conformal symmetry breaking in QED and QCD by analyzing specific stress-energy tensor correlators in momentum space, revealing massless poles and tensor structure degeneracies.

Contribution

It provides a detailed study of stress-energy tensor correlators in conformal field theory, highlighting quantum symmetry breaking signatures in QED and QCD.

Findings

Identification of massless poles indicating symmetry breaking

Analysis of tensor structure degeneracies in correlators

Application of reconstruction method for tensor correlators

Abstract

Conformal symmetry has important consequences for strong interactions at short distances and provides powerful tools for practical calculations. Even if the Lagrangians of Quantum Chromodynamics (QCD) and Electrodynamics (QED) are invariant under conformal transformations, this symmetry is broken by quantum corrections. The signature of the symmetry breaking is encoded in the presence of massless poles in correlators involving stress-energy tensors. We present a general study of the correlation functions $\langle TJJ\rangle$ and $\langle TTJJ\rangle$ of conformal field theory (CFT) in the flat background limit in momentum space, following a reconstruction method for tensor correlators. Furthermore, our analysis also focuses on studying the dimensional degeneracies of the tensor structures related to these correlators.