Determination of the ATLAS jet energy measurement uncertainty using photon-jet events in proton-proton collisions at sqrt{s} = 7 TeV

The ATLAS jet energy calibration is validated in-situ by exploiting the conservation of transverse momentum pT in events which contain a photon and a hadronic jet in the central region of the detector. Three jet calibration schemes derived from Monte Carlo simulation are validated using 38 ipb of proton-proton $(pp)$ collisions at sqrt{s}=7 TeV. Two techniques, which exhibit different systematic uncertainties, are used to measure jet response: direct pT balance pT^ jet / pT \gamma, and the Missing E_T Projection Fraction. For pT ^ \gamma > 45 GeV, the jet response measured in-situ agrees with simulation within 3%. With the current amount of data, this analysis is statistically limited beyond pT^\gamma of 250 GeV.