Search for the 125 GeV Standard Model Higgs Boson Decaying Via H→WW→lνjj at √s = 8 TeV

Abstract

The Higgs boson discovery was announced on July 4th, 2012. It was measured to have a mass of 125.7 ± 0.3 (stat) ± 0.3 (syst) GeV and since then boson has been seen in many decay paths, including the H→γγ, H→ZZ→4l, H→τ τ, and H→W⁺W⁻→lνlν channels. However, no one has looked for the boson at this mass using the H→W⁺W⁻→lνjj decay channel. This dissertation presents a search for the ∼125 GeV Higgs in semi-leptonic W decays using both traditional kinematically discriminating variables as well as a matrix element technique. The data for this analysis was collected in 2012 by the Compact Muon Solenoid (CMS) experiment at the Large Hadron Collider (LHC) and amounts to 19.7 fb⁻¹ of proton-proton collisions at a center of mass energy of 8 TeV. Although this analysis presents a step forward in complexity, we were still not able to see a significant excess above the standard model background prediction. However, we were able to set an upper limit of 5.4 on σ/σSM at the 95% confidence level for the semi-leptonic W decay of the Higgs boson. These represent some of the first such limits recorded.