Jet energy scale measurements and their systematic uncertainties in proton-proton collisions at root s=13 TeV with the ATLAS detector

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Jet energy scale measurements and their systematic uncertainties are reported for jets measured with the ATLAS detector using proton-proton collision data with a center-of-mass energy of $\sqrt{s}=13\text{ }\text{ }\mathrm{TeV}$, corresponding to an integrated luminosity of $3.2\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ collected during 2015 at the LHC. Jets are reconstructed from energy deposits forming topological clusters of calorimeter cells, using the anti-${k}_{t}$ algorithm with radius parameter $R=0.4$. Jets are calibrated with a series of simulation-based corrections and in situ techniques. In situ techniques exploit the transverse momentum balance between a jet and a reference object such as a photon, $Z$ boson, or multijet system for jets with $20<{p}_{\mathrm{T}}<2000\text{ }\text{ }\mathrm{GeV}$ and pseudorapidities of $|\ensuremath{\eta}|<4.5$, using both data and simulation. An uncertainty in the jet energy scale of less than 1% is found in the central calorimeter region ($|\ensuremath{\eta}|<1.2$) for jets with $100<{p}_{\mathrm{T}}<500\text{ }\text{ }\mathrm{GeV}$. An uncertainty of about 4.5% is found for low-${p}_{\mathrm{T}}$ jets with ${p}_{\mathrm{T}}=20\text{ }\text{ }\mathrm{GeV}$ in the central region, dominated by uncertainties in the corrections for multiple proton-proton interactions. The calibration of forward jets ($|\ensuremath{\eta}|>0.8$) is derived from dijet ${p}_{\mathrm{T}}$ balance measurements. For jets of ${p}_{\mathrm{T}}=80\text{ }\text{ }\mathrm{GeV}$, the additional uncertainty for the forward jet calibration reaches its largest value of about 2% in the range $|\ensuremath{\eta}|>3.5$ and in a narrow slice of $2.2<|\ensuremath{\eta}|<2.4$.