Study and Development of the CMS High Level Trigger and Muon Reconstruction Algorithms and Their Effects on the $pp \rightarrow\mu^{+}\mu^{-}jjjj$ Vector Boson Fusion Process

The work presented in this thesis covers the description and the performance studies of the muon reconstruction and simulation algorithms which I developed. More specifically: the simulation of the drift tube cell, the muon reconstruction within the DT chamber, the track reconstruction and muon identification with the whole CMS tracking system, are extensively discussed. The final aim of the work here presented was to obtain a high resolution on the observables of the $Z \rightarrow\mu^{+}\mu^{-}$ process, because the presence of the $Z$ particle in the final state is one of the important signatures of the $pp \rightarrow\mu^{+}\mu^{-}jjjj$ vector boson scattering channel. The vector boson scattering processes holds the key to investigate the electroweak symmetry breaking without any assumption on the breaking mechanism. A study of the $pp \rightarrow\mu^{+}\mu^{-}jjjj$ channel has been performed in order to assess the possibility of probing the symmetry breaking mechanism through the $VV$ fusion process using the CMS detector, with no assumption on the mechanism which restores the unitarity.