BFKL pomeron with massive gluons and running coupling

TL;DR

This paper numerically studies the BFKL Pomeron spectrum with massive gluons and running coupling, revealing its discrete nature and sensitivity to nonperturbative effects, especially in the leading pole.

Contribution

It introduces a numerical analysis of the BFKL equation with massive gluons and running coupling, highlighting the infrared sensitivity of the leading Pomeron and validating results with variational methods.

Findings

The Pomeron spectrum is discrete with a leading pole sensitive to nonperturbative effects.

Subleading poles are less sensitive and well-described by semiclassical methods.

The leading Pomeron shows infrared instability related to the running coupling.

Abstract

In this paper we proceed with the study of the Pomeron spectrum, by solving numerically the BFKL equation with massive gluons and running coupling. The spectrum of Regge singularities is discrete and the leading Pomeron has a considerable dependence on nonperturbative effects, for which we use Higgs mechanism as a model. We cross-checked this result with variational method and confirmed the infrared sensitivity of leading Pomeron. This fact is related to the infrared instability of the BFKL equation in QCD, with a running coupling. The subleading poles have a mild sensitivity to the soft physics, and are well described by known semiclassical methods. We also discuss the dependence on various prescriptions of the running coupling arguments.