Measurement of top quark properties from pair production and decay with the CMS detector

Semileptonic top quark pair decays are analysed using full simulation of the CMS detector at the proton{proton collider LHC. A complete analysis of event selection and reconstruc- tion is performed with the goal of the determination of di®erential cross sections. Special emphasis is put on object reconstruction and an e±cient and unbiased event selection procedure. The reconstruction of semileptonic t¹t decays uses the full combination of all reconstruc- tion objects. These objects are speci¯cally de¯ned and analysed in their reconstruction performance. For this several methods are developed and implemented. A highly e±cient electron identi¯cation and a clear procedure of lepton isolation are de¯ned. Two selections are compared, a cut-based and a neural network-based selection with a common e±ciency of 10%. For the event selection and reconstruction a kinematic ¯t is implemented. As ¯nal step the t¹t spectra of rapidity, invariant mass and transverse momentum are analysed.