Analytic Multi-Regge Theory and the Pomeron in QCD : II. Gauge Theory Analysis

TL;DR

This paper explores the high-energy behavior of gauge theories using Analytic Multi-Regge Theory, focusing on reggeon diagrams, symmetry restoration, and the role of massless fermions, especially in QCD with the Super-Critical Pomeron.

Contribution

It develops a reggeon diagram framework for unbroken gauge theories and analyzes symmetry restoration via infra-red limits, extending previous results to QCD.

Findings

Reproduces multi-regge amplitude structures from Part I.

Constructs reggeon diagrams for spontaneously-broken theories.

Shows unbroken gauge theories can be approached through infra-red limits.

Abstract

The high-energy Regge behavior of gauge theories is studied via the formalism of Analytic Multi-Regge Theory. Perturbative results for spontaneously-broken theories are first organised into reggeon diagrams. Unbroken gauge theories are studied via a reggeon diagram infra-red analysis of symmetry restoration. Massless fermions play a crucial role and the case of QCD involves the Super-Critical Pomeron as an essential intermediate stage. An introductory review of the build up of transverse momentum diagrams and reggeon diagrams from leading log calculations in gauge theories is presented first. It is then shown that the results closely reproduce the general structure for multi-regge amplitudes derived in Part I of the article, allowing the construction of general reggeon diagrams for spontaneously-broken theories. Next it is argued that, with a transverse-momentum cut-off, unbroken gauge theories can be reached through an infra-red limiting process which successively decouples fundamental representation Higgs fields . The first infra-red limit studied is the restoration of SU(2) gauge symmetry. The analysis is dominated by the exponentiation of divergences imposed by Reggeon Unitarity and the contribution of massless quarks ...