UC San Diego

In this thesis, we report the result on the search for the Standard Model(SM) Higgs boson decaying to a pair of W in the full leptonic final state using data collected by CMS detector at LHC at 7 and 8 TeV. The integrated luminosity is 4.9 /fb⁻¹ and 19.5 /fb⁻¹ at 7 and 8 TeV, respectively. The SM Higgs hypothesis is excluded at CLs=95 % in mH = 128 - 600 GeV. An excess of data is ob- served around mH = 125 GeV which corresponds to significance of 4.0[sigma] on the background-only hypothesis. The measured production rate normalized to the SM prediction is 0.76 ± 0.13(stat.) ± 0.16(syst.). A hypothesis test on the spin- parity nature of the new boson shows that data prefers SM Higgs boson to the graviton- like spin-2 model or spin-0 pseudo-scalar model