Plans for Jet Energy Corrections at CMS

Jet corrections at CMS will initially be derived from simulation tuned on test beam data, determined directly from collision data when available, and ultimately from a simulation tuned on collision data. The corrections will be factorized into a fixed sequence of sub-corrections associated with different detector and physics effects. The following three factors are minimum requirements for most analysis: offset corrections for pile-up and noise; correction for the response of the calorimeter as a function of jet pseudorapidity relative to the barrel; and correction for the absolute response as a function of transverse momentum in the barrel. The required correction gives a jet Lorentz vector equivalent to the sum of particles in the jet cone emanating from a QCD hard collision. The following additional factors will be provided for use if desired by the analysis: dependence on the fraction of jet energy in the electromagnetic calorimeter; dependence on the flavor of the final state jet; removal of underlying event energy; and correction back to the parton level. We discuss the current status of these corrections, the planned data-driven techniques for their derivation, and their anticipated evolution with the stages of the CMS experiment.