Resummation of clustering logarithms for non-global QCD observables

TL;DR

This paper develops an analytical method to resum clustering logarithms in non-global QCD observables, specifically for jet mass distributions, providing a significant improvement in theoretical predictions.

Contribution

It introduces an all-orders analytical resummation technique for clustering logs in jet observables, validated against numerical Monte Carlo results.

Findings

Clustering logs exponentiate at leading order.

Analytical resummation closely matches numerical simulations.

Resummation improves accuracy of QCD jet predictions.

Abstract

We address the problem of resumming leading clustering logs in QCD jet observables defined using the k_t, CA and SISCone algorithms. We specifically choose the jet mass distribution as an example and calculate up to order(alpha_s^4) clustering-log terms in the series expansion at single-log accuracy. These terms are found to exhibit a pattern of exponentiation and we are thus able to perform an all-orders analytical resummation for the clustering logs. We also numerically calculate the non-global logs at large N_c. We show that our result for the resummation of clustering logs is a very good analytical approximation to the numerical result obtained using a specialised Monte Carlo program.