Selection of Vector Boson Fusion Events in the $H\rightarrow\gamma\gamma$ Decay Channel Using an Inclusive Event Shape

Present-day measurements of the signal strength of the Higgs-boson production mode vector boson fusion tend to suffer from large theoretical uncertainties on the gluon fusion contamination in the vector boson fusion selection. The measurements are still limited by the statistical uncertainties, but as more data will be recorded, the statistical uncertainties will be reduced. Therefore it is of importance to think of alternative vector boson fusion selections with a better control over the theoretical uncertainty. Vector boson fusion selections use a central jet veto. Such a veto can be implemented via the inclusive event shape 2-jettiness as an alternative to the presently used central-jet veto. In this thesis, the properties of this event shape in $H\rightarrow\gamma\gamma$ events and its use in a vector boson fusion selection are examined. The theoretical uncertainties accompanying this event-shape based selection are studied. Finally, the vector boson fusion signal strength is determined using 8 TeV ATLAS data with a vector boson fusion selection which relies on cuts on the 2-jettiness.