Combined performance of Jets

Hadronic jets are the key observable for studying QCD effects. The precise and accurate reconstruction of jets is therefore of paramount importance to the study of QCD effects. Additionally the uncertainty on the jet energy scale forms the major uncertainty in many measurements studying QCD effects. The correlations of these uncertainties across phase space and the degree to which they are known is published with our measurements and the understanding of these is paramount when making statements about the degree of agreement of various calculations with the data. This talk will describe the derivation of the jet energy scale in ATLAS using di-jet, vector boson, and multijet events. The origin of the uncertainties will be described and how these are treated as correlated or not across phase space. Uncertainty sources dominated by Monte Carlo modeling will have particular focus.