Searches for the Higgs Boson at the LHC based on its couplings to Vector Bosons

One of the primary goals of the Large Hadron Collider (LHC) is the sea rch for the Higgs Boson. All Higgs searches rely heavily on Monte Carlo predic tions of both the signal and background processes. These simulations n ecessarily include models and assumptions not derived from first principles. Esp ecially the process of hadronization and the underlying event are only par tially un- derstood and differ strongly between different generators. As a r esult, the predictions can be wrong for special regions of phase space. Ther efore, pre- dictions by several programs should be compared to gain an estimat e of the uncertainty of the observables considered. In this work, two different Monte Carlo generators were compared in their pre- dictions for a Higgs search in the Vector Boson Fusion (VBF) Higgs pr oduction channel with subsequent decay into W bosons that decay leptonica lly in turn. A significant difference in the description of both signal and backgro und was found between the two generators. As the Monte Carlo description of the Vector Boson Fusion topology exhibits large uncertainties, it is important to validate the predictions with da ta. One background process to the VBF Higgs production is the production of Z bosons with jets. This process has a large cross section and therefore it is possible to validate its Monte Carlo description with early LHC data. The data tak en by the Compact Muon Solenoid (CMS) detector in 2010 amounts to 35 . 9 pb − 1 which yields a sufficient number of Z boson events. The Monte Carlo de - scription of these events was validated using the full CMS detector simulation. A good agreement between data and simulation could be found, makin g this process a first building block for the full VBF Higgs analysis. If the Higgs boson is heavier than about 200 GeV, it will predominantly decay into a pair of vector bosons. In case the Higgs boson decays into mu ons via Z bosons its reconstruction is very precise, as muons can be measur ed with a high accuracy. However, the branching ratio of this decay is below 1%, r esulting in a very small event yield. Including a Z boson decay into quarks leads to a drastically increased branching ratio, however this also strongly inc reases the amount of background events. A search strategy exploiting the f act that for Higgs boson masses above 350 GeV the Higgs decay products are bo osted and therefore are collimated in a relatively small solid angle is presented. In addition, this measurement allows to measure spin and CP quantum num- bers of a found heavy resonance based on the angular distribution s between the Z boson decay products.