Determination of the Top Quark Mass with a Template Method in the All Hadronic Decay Channel using 2.04/fb of ATLAS DATA

This note presents a measurement of the the top-quark mass from the all-hadronic ttbar decay channel using 2.04fb^-1 of ATLAS data. Fully hadronically decaying top quark pairs are selected from ATLAS data using two tagged b-quark jets and reconstructed by assigning jets according to their compatibility with the ttbar decay hypothesis. The top-quark mass is obtained by fitting templates to the three-jet mass combination of the selected jet triplets. The templates are obtained from combining a ttbar signal derived from Monte-Carlo simulation with a background contribution obtained from data by mixing jets from different events. Five different top-quark mass values have been simulated to construct a set of five templates which are used in the fit for the top-quark mass. This yields a top-quark mass of m_t = (174.9 +- 2.1 (stat.) +- 3.8 (syst.)) GeV in agreement with previous ATLAS results obtained from the the lepton+jets channel.