Energy resolution on trigger jets in the ATLAS experiment at the Large Hadron Collider

The most prominent high transverse-momentum products from proton-proton collisions at the Large Hadron Collider are collimated jets of hadrons. These jets are excellent probes for new physics at the LHC. This thesis presents a thorough investigation of the ATLAS jet energy resolutions of offline reconstructed jets as well as those of the high level trigger. The jet energy resolution is measured using a dijet balancing technique on jets reconstructed with different algorithms (anti-kT, cone) in the pseudorapidity region |η| < 2.5. Results from detailed Monte Carlo studies are compared with results from the collider data, based on up to 35 pb-1 of 7 TeV center-of-mass energy proton-proton collisions during the 2010 data taking run. Results show that the jet energy resolution obtained from Monte Carlo simulations agree with resolutions measured in data to within 10%.