High energy factorization at NLO: Lipatov's effective action revisited

TL;DR

This paper revisits Lipatov's high energy effective action to rigorously derive the two-loop gluon Regge trajectory, clarifying its definition through renormalization and detailing the self-energy calculation.

Contribution

It provides a rigorous derivation of the two-loop gluon Regge trajectory using Lipatov's effective action, enhancing theoretical understanding in high energy QCD.

Findings

Gluon Regge trajectory derived at two loops

Defined via renormalization of high energy divergence

Detailed calculation of the two-loop reggeized gluon self-energy

Abstract

We discuss aspects of our recent derivation of the gluon Regge trajectory at two loop from Lipatov's high energy effective action. We show how the gluon Regge trajectory can be rigorously defined through renormalization of the high energy divergence of the reggeized gluon propagator. We furthermore provide some details on the determination of the two-loop reggeized gluon self-energy.