Non-global logarithms in inter-jet energy flow with kt clustering requirement

TL;DR

The paper analyzes non-global logarithms in inter-jet energy flow and how kt clustering affects them. By combining fixed-order calculations with all-orders large-Nc Monte Carlo methods, it shows that kt clustering substantially reduces but does not eliminate non-global logarithms, preserving a buffer region around the gap. The results indicate a roughly 70% reduction in the phenomenological impact of non-global terms when clustering is applied, with remaining effects sensitive to the clustering radius. These findings inform how gaps-between-jets observables should be interpreted in HERA and similar experiments and motivate extending the study to more complex jet topologies like 4-jet systems.

Abstract

Recent work in inter-jet energy flow has identified a class of leading logarithms previously not considered in the literature. These so-called non-global logarithms have been shown to have significant numerical impact on gaps-between-jets calculations at the energies of current particle colliders. Here we calculate, at fixed order and to all orders, the effect of applying clustering to the gluonic final state responsible for these logarithms for a trivial colour flow 2 jet system. Such a clustering algorithm has already been used for experimental measurements at HERA. We find that the impact of the non-global logarithms is reduced, but not removed, when clustering is demanded, a result which is of considerable interest for energy flow observable calculations.