Towards an understanding of jet substructure

TL;DR

This paper provides the first analytical resummed calculations of jet substructure tagging rates, introduces improved tools with better analytical properties, and offers insights into their performance for distinguishing signal from background.

Contribution

It presents novel analytic calculations for jet substructure tools, including modifications that improve their theoretical and phenomenological behaviour.

Findings

Modified mass-drop tagger involves only single logarithms

Pruning modification enhances discrimination of signal and background

Results offer insights into the performance of existing jet substructure tools

Abstract

We present first analytic, resummed calculations of the rates at which widespread jet substructure tools tag QCD jets. As well as considering trimming, pruning and the mass-drop tagger, we introduce modified tools with improved analytical and phenomenological behaviours. Most taggers have double logarithmic resummed structures. The modified mass-drop tagger is special in that it involves only single logarithms, and is free from a complex class of terms known as non-global logarithms. The modification of pruning brings an improved ability to discriminate between the different colour structures that characterise signal and background. As we outline in an extensive phenomenological discussion, these results provide valuable insight into the performance of existing tools and help lay robust foundations for future substructure studies.