A precise measurement of the jet energy scale derived from single-particle measurements and in situ techniques in proton-proton collisions at $\sqrt{s}=$ 13 TeV with the ATLAS detector

TL;DR

This paper presents a highly precise jet energy calibration for the ATLAS detector at 13 TeV, combining single-particle measurements and in situ techniques to reduce uncertainties to below 1%.

Contribution

It introduces a new combined calibration method that achieves the most precise jet energy measurements with uncertainties as low as 0.3% at 300 GeV.

Findings

Jet calibration uncertainty is about 2.5% at 20 GeV and below 1% at higher energies.

The combined method yields a relative uncertainty of 0.3% at 300 GeV and 0.6% at 4 TeV.

Good agreement with previous $p_T$-balance methods confirms the calibration accuracy.

Abstract

The jet energy calibration and its uncertainties are derived from measurements of the calorimeter response to single particles in both data and Monte Carlo simulation using proton-proton collisions at $\sqrt{s} = 13$ TeV collected with the ATLAS detector during Run 2 at the Large Hadron Collider. The jet calibration uncertainty for anti-k$_t$ jets with a jet radius parameter of $R = 0.4$ and in the central jet rapidity region is about 2.5% for transverse momenta ($p_T$) of 20 GeV, about 0.5% for $p_T = 300$ GeV and 0.7% for $p_T = 4$ TeV. Excellent agreement is found with earlier determinations obtained from $p_T$-balance based in situ methods ($Z/\gamma$+jets). The combination of these two independent methods results in the most precise jet energy measurement achieved so far with the ATLAS detector with a relative uncertainty of 0.3% at $p_T = 300$ GeV and 0.6% at $4$ TeV. The jet energy calibration is also derived with the single-particle calorimeter response measurements separately for quark- and gluon-induced jets and furthermore for jets with $R$ varying from 0.2 to 1.0 retaining the correlations between these measurements. Differences between inclusive jets and jets from boosted top-quark decays, with and without grooming the soft jet constituents, are also studied.