Jet Performance in pp Collisions at 7 TeV

We present the techniques adopted by CMS to measure the jet energy response and resolutions. Results from detailed Monte Carlo studies are compared with preliminary observations from the collider data based on up to 73~nb$^{-1}$ of proton-proton LHC collisions at 7~TeV center of mass energy. Studies for jet energy response and resolutions are presented for three different approaches to reconstruct jets in the CMS detector: calorimeter-only based jet reconstruction; the "Jet-Plus-Track" algorithm, which improves the measurement of calorimeter jets by exploiting the associated tracks; and the "Particle Flow" method, which aims to reconstruct each particle in the event based on information from all sub-detectors, prior to the jet clustering. Current physics analyses in CMS use 10\% (5\%) jet calibration uncertainties for calorimeter jets (Jet-Plus-Track and Particle Flow jets), with the additional 2\% uncertainty per unit rapidity. Observations from the current limited statistics datasets support these numbers as conservative estimates. The 10\% uncertainties are used for evaluation of the systematic errors due to the jet resolutions effects for all three jet types. Observations from the data support this number as a reasonable estimate.