A theory of jet definition

TL;DR

This paper develops a first-principles framework for defining jets in particle physics, optimizing for minimal errors and hadronization effects, and introduces a flexible, theoretically grounded jet algorithm with practical computational advantages.

Contribution

It presents a systematic, first-principles-based jet definition framework that generalizes existing algorithms with dynamic shapes and minimal ad hoc assumptions.

Findings

Proposes a jet definition optimized for detector errors and hadronization.

Introduces a shape observable generalizing thrust for multiple axes.

Provides a computationally efficient implementation.

Abstract

A systematic framework for jet definition is developed from first principles of physical measurement, quantum field theory, and QCD. A jet definition is found which: is theoretically optimal in regard of both minimization of detector errors and inversion of hadronization; is similar to a cone algorithm with dynamically negotiated jet shapes and positions found via shape observables that generalize the thrust to any number of axes; involves no ad hoc conventions; allows a fast computer implementation [hep-ph/9912415]. The framework offers an array of options for systematic construction of quasi-optimal observables for specific applications.