# Jet energy measurement and its systematic uncertainty in proton–proton collisions at √s=7TeV with the ATLAS detector

 Title: Jet energy measurement and its systematic uncertainty in proton–proton collisions at √s=7TeV with the ATLAS detector Author: Franklin, Melissa; Huth, John; Jeanty, L; Lopez Mateos, D; Mercurio, Kevin ; Morii, Masahiro; Spearman, William; Yen, Andy; Zevi Della Porta, G Note: Order does not necessarily reflect citation order of authors. Citation: ATLAS Collaboration. 2015. “Jet Energy Measurement and Its Systematic Uncertainty in Proton–proton Collisions at √s=7TeV With the ATLAS Detector.” The European Physical Journal C 75 (1) (January). doi:10.1140/epjc/s10052-014-3190-y. Full Text & Related Files: 10.1140%2Fepjc%2Fs10052-014-3190-y.pdf (6.580Mb; PDF) Abstract: The jet energy scale (JES) and its systematic uncertainty are determined for jets measured with the ATLAS detector using proton–proton collision data with a centre-of-mass energy of s√=7 TeV corresponding to an integrated luminosity of 4.7 fb −1 . Jets are reconstructed from energy deposits forming topological clusters of calorimeter cells using the anti- kt algorithm with distance parameters R=0.4 or R=0.6 , and are calibrated using MC simulations. A residual JES correction is applied to account for differences between data and MC simulations. This correction and its systematic uncertainty are estimated using a combination of in situ techniques exploiting the transverse momentum balance between a jet and a reference object such as a photon or a Z boson, for 20≤pjetT<1000 GeV and pseudorapidities |η|<4.5 . The effect of multiple proton–proton interactions is corrected for, and an uncertainty is evaluated using in situ techniques. The smallest JES uncertainty of less than 1 % is found in the central calorimeter region ( |η|<1.2 ) for jets with 55≤pjetT<500 GeV . For central jets at lower pT , the uncertainty is about 3 %. A consistent JES estimate is found using measurements of the calorimeter response of single hadrons in proton–proton collisions and test-beam data, which also provide the estimate for pjetT>1 TeV. The calibration of forward jets is derived from dijet pT balance measurements. The resulting uncertainty reaches its largest value of 6 % for low- pT jets at |η|=4.5 . Additional JES uncertainties due to specific event topologies, such as close-by jets or selections of event samples with an enhanced content of jets originating from light quarks or gluons, are also discussed. The magnitude of these uncertainties depends on the event sample used in a given physics analysis, but typically amounts to 0.5–3 %. Published Version: doi:10.1140/epjc/s10052-014-3190-y Terms of Use: This article is made available under the terms and conditions applicable to Other Posted Material, as set forth at http://nrs.harvard.edu/urn-3:HUL.InstRepos:dash.current.terms-of-use#LAA Citable link to this page: http://nrs.harvard.edu/urn-3:HUL.InstRepos:33839898 Downloads of this work: