A functional RG approach for the BFKL Pomeron

TL;DR

This paper develops a functional renormalization group framework to analyze the BFKL Pomeron in QCD, aiming to understand high-energy scattering and the transition to an effective reggeon field theory.

Contribution

It introduces a novel IR-regulated effective action approach for the BFKL Pomeron using functional RG equations with a specific non-local vertex truncation.

Findings

Numerical analysis of the BFKL Pomeron spectrum with an IR regulator.

Insights into the properties of leading poles in high energy scattering.

Understanding the transition to a local reggeon field theory at larger distances.

Abstract

In this paper we encode the perturbative BFKL leading logarithmic resummation, relevant for the Regge limit behavior of QCD scattering amplitudes, in the IR-regulated effective action which satisfies exact functional renormalization group equations. This is obtained using a truncation with a specific infinite set of non local vertices describing the multi-Regge kinematics (MRK). The goal is to use this framework to study, in the high energy limit and at larger transverse distances the transition to a much simpler effective local reggeon field theory, whose critical properties were recently investigated in the same framework. We perform a numerical analysis of the spectrum of the BFKL Pomeron deformed by the introduction of a Wilsonian infrared regulator to understand the properties of the leading poles (states) contributing to the high energy scattering.