Chiral-symmetry breaking and confinement in Minkowski space

TL;DR

This paper develops a Minkowski-space quark-antiquark interaction model using Covariant Spectator Theory, demonstrating chiral symmetry, comparing with lattice QCD, and calculating the pion form factor consistent with experimental data.

Contribution

It introduces a Minkowski-space model for quark interactions that satisfies chiral symmetry constraints and connects with lattice QCD and experimental results.

Findings

Quark mass function matches lattice QCD data.

Model satisfies Adler-zero chiral symmetry constraint.

Electromagnetic pion form factor agrees with JLab data.

Abstract

We present a model for the quark-antiquark interaction formulated in Minkowski space using the Covariant Spectator Theory. The quark propagators are dressed with the same kernel that describes the interaction between different quarks. By applying the axial-vector Ward-Takahashi identity we show that our model satisfies the Adler-zero constraint imposed by chiral symmetry. For this model, our Minkowski-space results of the dressed quark mass function are compared to lattice QCD data obtained in Euclidean space. The mass function is then used in the calculation of the electromagnetic pion form factor in relativistic impulse approximation, and the results are presented and compared with the experimental data from JLab.