Probing the measurement of jet energies with the ATLAS detector using Z+jet events from proton-proton collisions at sqrt(s) = 7 TeV

The energy calibration of jets measured with the ATLAS detector at the LHC is probed in situ using the direct transverse momentum balance pT(jet)/pT(Z) between a jet in the central region of the detector (|eta| < 1.2) and a Z boson decaying into an e+e− pair. Two calibration schemes are studied using a data set corresponding to an integrated luminosity of 4.7 fb−1 of proton-proton collisions at a centre-of-mass energy of sqrt(s) = 7 TeV. The analysis is carried out for pT(Z) between 17 GeV and 260 GeV. The pT balance measured in the data is a few percent lower than in the simulation. The precision achieved with this in situ method is about 10% at low pT and 1% to 2% for pT > 30 GeV.