Exploring the Space of Jets with CMS Open Data

TL;DR

This paper analyzes the space of jets using CMS Open Data, validating detector performance, comparing with simulations, and employing the energy mover's distance to explore jet configurations and their metric space.

Contribution

It introduces novel analyses of jet metric space using EMD on CMS Open Data, providing datasets and code for future research.

Findings

Good agreement between data and simulations for track-based observables

EMD effectively quantifies detector effects and jet similarities

Identifies typical and atypical jet configurations

Abstract

We explore the metric space of jets using public collider data from the CMS experiment. Starting from 2.3/fb of 7 TeV proton-proton collisions collected at the Large Hadron Collider in 2011, we isolate a sample of 1,690,984 central jets with transverse momentum above 375 GeV. To validate the performance of the CMS detector in reconstructing the energy flow of jets, we compare the CMS Open Data to corresponding simulated data samples for a variety of jet kinematic and substructure observables. Even without detector unfolding, we find very good agreement for track-based observables after using charged hadron subtraction to mitigate the impact of pileup. We perform a range of novel analyses, using the "energy mover's distance" (EMD) to measure the pairwise difference between jet energy flows. The EMD allows us to quantify the impact of detector effects, visualize the metric space of jets, extract correlation dimensions, and identify the most and least typical jet configurations. To facilitate future jet studies with CMS Open Data, we make our datasets and analysis code available, amounting to around two gigabytes of distilled data and one hundred gigabytes of simulation files.