Regge theory in hadron physics

TL;DR

This paper offers a comprehensive, pedagogical overview of Regge theory's role in hadron physics, covering fundamental concepts, historical context, and recent applications in QCD phenomenology.

Contribution

It provides a clear, accessible introduction to Regge theory, connecting classical scattering concepts with modern QCD applications and highlighting recent developments.

Findings

Clarifies the role of analyticity in scattering amplitudes

Reviews historical and modern applications of Regge theory in QCD

Discusses the analysis of resonances in the complex angular momentum plane

Abstract

We provide a pedagogical introduction to Regge theory as it pertains to the study of hadrons and their interactions. We clarify the fundamental concepts of analyticity in the complex angular momentum plane and their implications for scattering amplitudes. We highlight historical developments that significantly shaped our understanding of scattering theory and the strong interaction, both before and following the discovery of QCD. We end with a review of more recent applications of Regge theory in QCD phenomenology, including describing exchange processes, constraining low-energy amplitudes, and analyzing resonances in the complex angular momentum plane.