The main interest of the physics analysis work of the MPI SCT group is the investigation of the top quark pair production process, and particularly the determination of the mass of the top quark in the reaction (top anti-top) to (bottom W+ anti-bottom W-) utilizing the W-Boson pair decay to (lepton neutrino quark-quark') where lepton can be either an electron or muon.
In this particular decay the charged leptons with high transverse momenta from the decay of one W-Boson are utilized to identify the event and to suppress background reactions. The mass of the top quark is obtained from the hadronic decay of the second W-Boson and the corresponding b-jet.
Based on generated events from the MC@NLO Monte Carlo program an initial analysis has been performed to obtain the mass of the top quark. For each event, the four jets with the highest transverse momenta are assumed to stem from the (bottom anti-bottom) and (quark-quark') systems. They are grouped to obtain the best estimate of the masses of the hadronically decaying W-Boson and the associated top quark. The central value of the fitted spectrum as well as the width of the distribution strongly depend on the choice of the jet algorithm and jet steering parameters, the calibration of the calorimeters and various other details of the analysis which are under study.