Simultaneous measurements of $N$-subjettiness observables in jets from gluons and light-flavour quarks, and in decays of boosted W bosons and top quarks

TL;DR

This paper presents a comprehensive measurement of 25 jet substructure observables in high-energy proton-proton collisions, providing detailed data to improve theoretical models of jet radiation and structure.

Contribution

It introduces a simultaneous measurement of multiple N-subjettiness observables in jets from various sources, including gluons, light quarks, and boosted W and top decays, with detailed particle-level correlations.

Findings

Measured 25 substructure observables in jets from different processes.

Unfolded results to stable particle level for systematic comparisons.

Provided particle-level correlations to refine jet radiation models.

Abstract

A simultaneous measurement of 25 substructure observables is presented using large-radius jets with high transverse momentum from proton-proton collisions at $\sqrt{s}$ = 13 TeV. The measurement is carried out on dijet events and $\mathrm{t\bar{t}}$ events enriched in Lorentz-boosted W bosons and top quarks decaying hadronically. The three data samples consist of jets with one, two, or three prongs from the showering and hadronization of a gluon or light-flavour quark, two quarks, or three quarks, respectively. The data correspond to an integrated luminosity of 138 fb$^{-1}$, recorded by the CMS experiment in 2016$-$2018. A detailed characterization of the jet substructure is provided using a 6-body basis of $N$-subjettiness observables that overconstrains the phase space of the resolved emissions in the jet. The measurements are unfolded to the level of stable particles, and an estimate of the particle-level correlations between observables is provided, ensuring that the results can be used to systematically assess and refine the modelling of radiation in jets.