Same sign dimuon search for heavy majorana mass neutrinos at the CMS experiment at Cern and design studies of a quartz plate calorimeter prototype

This paper consists of two studies: the results of a search for heavy Majorana neutrinos (N) using an event signature dened by two like-sign charged muons and two jets, and the results from studies of a prototype quartz plate calorimeter. The data in the Majorana search correspond to an integrated luminosity of 5.0 inverse fb of pp collisions at a centre-of-mass energy of 7 TeV collected with the CMS detector at the Large Hadron Collider. No excess of events are observed beyond the expected standard model background and therefore upper limits are set on the square of the mixing element, |V_μN|^2 as a function of Majorana neutrino mass. These are the first direct upper limits on the heavy Majorana-neutrino mixing for m_N 90GeV. The second part of this thesis is the results of performance tests of a 20-layer quartz plate calorimeter prototype. The calorimeter prototype was tested at the CERN H2 area in hadronic and electromagnetic congurations, at various energies of pion and electron beams. The beam test and simulation results of this prototype are reported.