Is BFKL factorization valid for Mueller-Tang jets?

TL;DR

This paper investigates the validity of BFKL factorization in Mueller-Tang jet production at high energies, revealing potential violations and their implications for LHC phenomenology, especially concerning non-singlet exchange contributions.

Contribution

It provides a detailed analysis of factorization violations at NLL order and assesses the significance of non-singlet exchanges in Mueller-Tang jet processes.

Findings

BFKL factorization may be violated at NLL order with IR safe jets.

Non-singlet exchanges can compete with singlet contributions at low rapidity.

Quantitative impact on LHC jet phenomenology is estimated.

Abstract

The perturbative QCD description of high-energy hadroproduction of two hard jets separated by a large rapidity gap void of emission (also called Mueller-Tang jets) is based on a factorization formula of BFKL type that represents exchanges of colour-singlet objects among the external particles. This formula resums to all perturbative orders a certain class of Feynman diagrams that are supposed to dominate the cross-section in the Regge limit. However, the explicit calculations at next-to-leading logarithmic order questions the validity of such factorization when an IR safe jet algorithm is used to reconstruct jets. We show the origin of such violation of factorization, and quantify its impact for LHC phenomenology. In this connection, we estimate the impact of other contributions to the cross-section that are not included in the Mueller-Tang factorization formula -- colour non-singlet exchanges -- that, at low rapidity separation, compete with the singlet ones.