Hadronic structure on the light-front I.\ Instanton effects and quark-antiquark effective potentials

TL;DR

This paper introduces a model based on dense instanton ensembles to explain non-perturbative quark interactions in mesons, aiming to understand the origin of central and spin-dependent forces in QCD.

Contribution

It proposes a novel instanton-based model for the QCD vacuum to explain interquark forces in mesons, with future work extending to light-front dynamics.

Findings

A dense instanton ensemble model for the QCD vacuum.

Explanation of interquark forces from quarkonia to light mesons.

Foundation for deriving light-front Hamiltonians and wavefunctions.

Abstract

This is the first of a sequence of papers that address the non-perturbative origin of the central, and spin-dependent forces between quarks. Its main thrust is a focus on meson spectroscopy in the center of mass frame. We suggest a "dense instanton ensemble" model for the QCD vacuum, to explain the interquark forces in mesons, from quarkonia to heavy-light and light-light ones, to the extent it is possible. The sequels will show how to export these interactions to the light front, and derive the corresponding Hamiltonians and mesonic wavefunctions.