High-energy factorization via eigenfunctions of the next-to-leading-order BFKL kernel

TL;DR

This paper develops a formula for forward exclusive hadronic process amplitudes in perturbative QCD using next-to-leading order BFKL eigenfunctions, addressing formal subtleties and analyzing numerical stability in electroproduction of vector mesons.

Contribution

It introduces a general amplitude formula based on NLO BFKL eigenfunctions and examines its formal consistency and numerical stability in specific processes.

Findings

The NLO eigenfunction-based formula is consistent with leading-order approaches.

Numerical stability varies depending on the eigenfunction set used.

Formal subtleties in the compatibility check are discussed.

Abstract

We present a general formula for the amplitude of forward exclusive hadronic processes in the semihard regime of perturbative Quantum Chromodynamics (QCD), by means of the {\em next-to-leading order} eigenfunctions of the Balitsky-Fadin-Kuraev-Lipatov (BFKL) kernel, as constructed by Chirilli and Kovchegov. We discuss some formal subtleties in the check of compatibility with the similar formula based on the use of the {\em leading-order} BFKL eigenfunctions. Finally, in the specific case of the electroproduction of two light vector mesons, we consider the numerical stability of the amplitude when one or the other set of eigenfunctions is adopted.