QCD dynamics in mesons at soft and hard scales

TL;DR

This paper investigates QCD phenomena across soft and hard scales using Dyson-Schwinger equations, analyzing meson properties, chiral condensates, and parton distributions to deepen understanding of non-perturbative effects.

Contribution

It applies a unified Dyson-Schwinger approach to study soft and hard QCD phenomena in mesons, connecting non-perturbative and perturbative regimes.

Findings

Estimate of the four-quark chiral condensate

Identification of the non-perturbative onset scale in QCD

Analysis of valence quark distributions in pions and kaons

Abstract

Using a ladder-rainbow kernel previously established for the soft scale of light quark hadrons, we explore, within a Dyson-Schwinger approach, phenomena that mix soft and hard scales of QCD. The difference between vector and axial vector current correlators is examined to estimate the four quark chiral condensate and the leading distance scale for the onset of non-perturbative phenomena in QCD. The valence quark distributions, in the pion and kaon, defined in deep inelastic scattering, and measured in the Drell Yan process, are investigated with the same ladder-rainbow truncation of the Dyson-Schwinger and Bethe-Salpeter equations.