Using HERA Data to Determine the Infrared Behaviour of the BFKL Amplitude

TL;DR

This paper analyzes the infrared behavior of the BFKL amplitude using HERA data, providing insights into gluon dynamics at low x and low transverse momenta, and exploring potential signals of new physics.

Contribution

It introduces a discrete pomeron solution approach to describe HERA data and determine the unintegrated gluon density at low transverse momenta.

Findings

Excellent fit to HERA data at low x

Determination of unintegrated gluon density below 100 GeV^2

Sensitivity of amplitude phases to non-perturbative gluonic effects

Abstract

We determine the infrared behaviour of the BFKL forward amplitude for gluon-gluon scattering. Our approach, based on the discrete pomeron solution, leads to an excellent description of the new combined inclusive HERA data at low values of x (<0.01) and at the same time determines the unintegrated gluon density inside the proton, for squared transverse momenta of the gluon less than 100 GeV^2. The phases of this amplitude are sensitive to the non-perturbative gluonic dynamics and could be sensitive to the presence of Beyond-the-Standard-Model particles at very high energies.