Multijet event shape variables for Mueller Navelet jet topologies

TL;DR

This paper introduces new multijet event shape variables to analyze Mueller-Navelet jet topologies, comparing BFKL-based predictions with NLO calculations, and finds compatibility at current LHC energies with notable differences at higher multiplicities.

Contribution

It presents novel multijet event shape variables and compares BFKL and NLO predictions, enhancing understanding of high-energy QCD in Mueller-Navelet jet events.

Findings

BFKL and NLO predictions are compatible at current LHC energies.

Differences emerge with increased jet multiplicity or lower transverse momentum.

The BFKL approach reliably describes high-energy strong interactions.

Abstract

This paper presents a new set of multijet event shape variables introduced to further understand the Mueller-Navelet jet topology. This topology consists of having at least one pair of jets with a very large rapidity separation between them, treating additional jet activity inclusively. This multijet topology is expected to shed light on the radiation pattern that is expected in the high-energy limit of the strong interaction. The paper relies on a Monte Carlo event generator analysis. One set of predictions uses the BFKLex event generator, which is based on Balitsky-Fadin-Kuraev-Lipatov (BFKL) perturbative quantum chromodynamics (pQCD) evolution with a resummation of large logarithms of energy at leading-logarithmic accuracy. The BFKLex predictions are compared with a fixed-order next-to-leading order pQCD calculation using POWHEG matched to the parton shower of PYTHIA8 (NLO+PS), which is the standard for NLO generator predictions at the LHC. We find that both approaches lead to compatible results at current LHC energies, assuming the current experimental constraints for the reconstruction of low transverse momentum jets in ATLAS and CMS. This shows the reliability of the BFKL approach at describing the behavior of the strong interaction in the preasymptotic limit of high center-of-mass energies. Differences between the NLO+PS and the BFKL-based approaches are found when the jet multiplicity is increased or when the minimum transverse momentum of the jets is decreased.