Influence of broken flavor and C and P symmetry on the quark propagator

TL;DR

This paper investigates how explicit breaking of C and P symmetries in QCD, especially under extreme conditions, affects the quark propagator using Dyson-Schwinger equations, revealing non-linear amplification of symmetry-breaking effects.

Contribution

It introduces a non-perturbative study of the quark propagator with explicit C and P symmetry breaking across all quark masses using Dyson-Schwinger equations.

Findings

Weak breaking effects align with perturbative trends.

Moderate to strong breaking causes non-linear, amplified effects.

Symmetry breaking significantly alters tensor structures in the propagator.

Abstract

Embedding QCD into the standard model breaks various symmetries of QCD explicitly, especially C and P. While these effects are usually perturbatively small, they can be amplified in extreme environments like merging neutron stars or by the interplay with new physics. To correctly treat these cases requires fully backcoupled calculations. To pave the way for later investigations of hadronic physics, we study the QCD quark propagator coupled to an explicit breaking. This substantially increases the tensor structure even for this simplest correlation function. To cope with the symmetry structure, and covering all possible quark masses, from the top quark mass to the chiral limit, we employ Dyson-Schwinger equations. While at weak breaking the qualitative effects have similar trends as in perturbation theory, even moderately strong breakings lead to qualitatively different effects, non-linearly amplified by the strong interactions.