Measuring the number of hadronic jets

TL;DR

This paper introduces a set of infrared finite shape observables, called jet discriminators, to quantitatively measure the number of hadronic jets, providing stable, theoretically motivated tools for analyzing multi-hadron final states.

Contribution

It proposes a new sequence of jet discriminators that are stable, continuous, and theoretically motivated, improving the quantitative analysis of multi-hadron final states.

Findings

Jet discriminators take values between 0 and 1.

They are stable against small variations of input data.

They are formulated as multiparticle correlators compatible with quantum field theory.

Abstract

A quantitative description of the qualitative feature of multi-hadron final states known as the "number of jets" is given by a sequence of infrared finite shape observables (jet discriminators) that: take continuous values between 0 and 1; are stable-unlike clustering algorithms-against small variations of the input (data errors, Sudakov effects etc.); have a form of multiparticle correlators that is natural in the context of quantum field theory and hence are better suited for a systematic study of theoretical uncertainties (logarithmic and power corrections).