Color symmetry and confinement as an underlying superconformal structure in holographic QCD

TL;DR

This paper explores how holographic QCD, incorporating superconformal symmetry in AdS space, provides insights into confinement, mass scale emergence, and supersymmetric relations among hadron states, connecting theory with experimental phenomena.

Contribution

It introduces a superconformal symmetry framework in holographic QCD that explains confinement and hadron mass scales, and relates meson, baryon, and tetraquark trajectories.

Findings

Superconformal symmetry in AdS space explains confinement.

Supersymmetric relations link different hadron trajectories.

Implications for QCD color transparency are discussed.

Abstract

Dedicated to the memory of our colleague, Harald Fritzsch, who, together with Murray Gell-Mann, introduced the color quantum number as the exact symmetry responsible for the strong interaction, thus establishing quantum chromodynamics (QCD) as a fundamental non-Abelian gauge theory. A basic understanding of hadron properties, however, such as confinement and the emergence of a mass scale, from first principles QCD has remained elusive: Hadronic characteristics are not explicit properties of the QCD Lagrangian and perturbative QCD, so successful in the large transverse momentum domain, is not applicable at large distances. In this article, we shall examine how this daunting obstacle is overcome in holographic QCD with the introduction of a superconformal symmetry in anti de Sitter (AdS) space which is responsible for confinement and the introduction of a mass scale within the superconformal group. When mapped to light-front coordinates in physical spacetime, this approach incorporates supersymmetric relations between the Regge trajectories of meson, baryon and tetraquark states which can be visualized in terms of specific $SU(3)_C$ color representations of quarks. We will also briefly discuss here the implications of holographic models for QCD color transparency in view of the present experimental interest. Based on the invited contribution to the book dedicated to the memory of Harald Fritzsch.