Determination of the jet energy scale corrections for the low pt jets in proton- proton collisions at √𝒔 = 13 tev with the cms experiment

In this thesis, two analyses related to jet energy scale corrections focus on the low pT region are performed. The first part of the thesis is dedicated to the Monte Carlo (MC) truth jet energy corrections for 2015 no pileup QCD PYTHIA8 sample. Particle-Flow Charged Hadron Subtraction (PFCHS) jets are reconstructed by using the anti-kT clustering algorithm with the cone size parameters of 0.4. The study is performed in the pseudorapidity region of |η| < 5.191 and jet pT region of 10 < pT < 905 GeV. The second part presents the calibration of the jet energy scale with respect to residual differences between data and simulation after simulation-based pre-calibrations is applied. This correction is called as L2 relative residual jet energy correction. In this analysis, √𝑠 = 13 TeV low pileup data of 2015 and PYTHIA8 MC samples are used. The correction factors depending on jet pT and h are derived by using two different methods based on the dijet final states in the region of |η| < 5.191 pseudorapidity and 20 < pT < 114 GeV. This will make an important contribution to the analysis to be performed using the low pT jets in the physics analysis.