Lipatov's Effective Action Beyond Tree Level

TL;DR

This paper discusses the extension of Lipatov's high-energy effective action beyond tree level, detailing the necessary regularization and counterterms with examples at one- and two-loop levels.

Contribution

It provides a systematic prescription for regularization and counterterms in Lipatov's effective action beyond tree level, supported by explicit loop calculations.

Findings

Regularization and counterterms are essential beyond tree level.

One- and two-loop examples demonstrate the prescription.

Enhances the applicability of Lipatov's effective theory.

Abstract

Computations in Quasi-Multi-Regge kinematics are much simplified using an effective theory pioneered by Lipatov. This high-energy effective theory does not come from an integrating out procedure, and suitable counterterms and regularization have to be provided beyond tree level. In this note we explain this prescription and illustrate it with one- and two-loop examples.