Search for new resonances in p-p collisions using fully leptonic W+W- decays with the CMS detector

This thesis presents a search for a possible heavy Higgs boson, X, decaying into apair of W bosons, in the mass range from 200 GeV to 3 TeV. The analysis is based onproton-proton collisions recorded by the CMS experiment at the CERN LHC in 2016,√corresponding to an integrated luminosity of 35.9 fb−1 at s =13 TeV. The W bosonpair decays are reconstructed in the 2 2ν and νq q final states. Both gluon-gluon¯fusion and electroweak production of the scalar resonance are considered. Dedicatedevent categorizations, based on the kinematic properties of the final states, areemployed for an optimal signal-to-background separation. Combined upper limits atthe 95% confidence level on the product of the cross section and branching fractionexcludes a heavy Higgs boson with Standard Model-like couplings and decays in therange of mass investigated.