Search for the Stueckelberg Z' decaying into dimuon pairs at CMS/LHC

This thesis describes a search for a new particle with narrow decay width decaying into dimuon pairs. In 2012 and 2011, the Large Hadron Collider produced proton-proton collisions. The CMS detector at the CERN laboratory recorded about 5 inverse fb-1 integrated luminosity at a center-of-mass energy of 7 TeV and about inverse 20 fb-1 at sqrt(s)=8 TeV. The upper limits on the ratio of the cross section times dimuon branching fraction of the Stueckelberg Z' boson to that of the standard model Z boson are determined at the 95% confidence level by the Bayesian technique. The parallel analysis in the dielectron channel is combined with this dimuon analysis. The combined result excludes, at 95% confidence level, the Stueckelberg Z' boson with = 0.06(0.04) lighter than 890(540) GeV based on the CMS data recorded in 2011. The Stueckelberg Z' boson excluded parameter space, at 95% confidence level, is given in a (mass,epsilon) and (Cd,Cu) combined plot.