Measurement of the Jet Energy Scale in the CMS experiment ... - IIHE

138 SUMMARYAlso the method of estimating the residual jet energy calibration factors has beenapplied on the real proton collisions recorded by the CMS experiment in 2010. Theestimated results on the simulation and real proton collisions are summarized below.There is a good agreement between simulation and data and the residual correctionsare found to be equal.simulationdata∆ε est∆ε estl(%) -8.1±2.4(stat.)±0.9(sys.) -8.6±2.7(stat.)b(%) -3.2±3.5(stat.)±1.0(sys.) -5.0±3.9(stat.)Table 6.2: The final estimated residual jet energy corrections obtained in the 36.1pb −1data set. The statistical uncertainties are corrected for the non-unity width of the pulldistributions.Compared to the residual calibration factors provided by other data driven methodssuch as QCD dijet events, the gain that can be obtained by applying the calibrationmethod of this thesis is twofold. A first one is that the calibration method described inthis analysis is able to provide the residual jet energy corrections which is differentiatedwith respect to the flavour of quarks, namely light quark jets and b quark jets. A secondone is that, while the methods based on QCD dijet events determine the residual jetenergy corrections and correct the energy of the jets back to the generator level jets,the method which is described in this thesis is able to calibrate the energy of the jetsback to the energy of the initiating quarks, instead of the generator level jets.