Browsing by Subject "Standard Model"

The Standard Model is one of the accurate theories that we have. It has demonstrated its success by predictions and discoveries of new particles such as the existence of gauge bosons W and Z and heaviest quarks charm, bottom and top. After discovery of the Higgs boson in 2012 Standard Model became complete in sense that all elementary particles contained in it had been observed. In this thesis I will cover the particle content and interactions of the Standard Model. Then I explain Higgs mechanism in detail. The main feature in Higgs mechanism is spontaneous symmetry breaking which is the key element for this mechanism to work. The Higgs mechanism gives rise to mass of the particles, especially gauge bosons. Higgs boson was found at the Large Hadron Collider by CMS and ATLAS experiments. In the experiments, protons were collided with high energies (8-13 TeV). This leads to production of the Higgs boson by different production channels like gluon fusion (ggF), vector boson fusion (VBF) or the Higgsstrahlung. Since the lifetime of the Higgs boson is very short, it cannot be measured directly. In the CMS experiment Higgs boson was detected via channel H → ZZ → 4l and via H → γγ. In this thesis I examine the correspondence of the Standard Model to LHC data by using signal strengths of the production and decay channels by parametrizing the interactions of fermionic and bosonic production and decay channels. Data analysis carried by least squares method gave confidence level contours that describe how well the predictions of the Standard Model correspond to LHC data