Studies on the top quark mass measurement in the all-hadronic top-antitop decay channel with ATLAS

Prospects for measuring the top quark mass in the top-antitop all-hadronic channel with the ATLAS detector are investigated. A robust analysis is developed on Monte Carlo simulations at sqrt{s} = 10 TeV, considering 200 pb−1 of integrated luminosity. The event selection is based on a set of topological variables and on two b-tagged jets. The top quark mass is measured by a chi^{2} fitting procedure on the reconstructed invariant mass distribution and the fit result is corrected for missing b-jet energy calibration. With a top quark mass of mMC = 172.5 GeV as input to the simulation, the proposed method yields to a result of mt = 173.4 ± 2.1|stat ± 7.3|sys GeV for a typical pseudo-experiment. The main contribution to the systematic error comes from the jet energy scale uncertainty. Studies on the performance of the jet calibration method used, called Local Hadron Calibration, are performed both with Monte Carlo simulations and with first ATLAS data collected for pp collisions at sqrt{s} = 900 GeV.