Evidence for the Discrete Asymptotically-Free BFKL Pomeron from HERA Data

TL;DR

This paper demonstrates that the asymptotically-free BFKL Pomeron model, with discrete singularities, accurately fits HERA data on small-x virtual photoproduction, supporting its validity in describing high-energy QCD phenomena.

Contribution

It provides the first detailed fit of HERA data using the discrete BFKL Pomeron with next-to-leading-order corrections, confirming its relevance in small-x physics.

Findings

The discrete BFKL Pomeron reproduces the Q^2 dependence of HERA data.

A three-singularity fit matches both Q^2 and x dependence of the data.

The phase of BFKL wavefunctions is fixed at an infrared scale.

Abstract

We show that the next-to-leading-order renormalization-group-improved asymptotically-free BFKL Pomeron provides a good fit to HERA data on virtual photoproduction at small x and large Q^2. The leading discrete Pomeron pole reproduces qualitatively the Q^2 dependence of the HERA data for x ~10^{-3}, and a fit using the three leading discrete singularities reproduces quantitatively the Q^2 and x dependence of the HERA data for x < 10^{-2}. This fit fixes the phase for all the BFKL wavefunctions at a chosen infrared scale.