Observation of electroweak W+jets production and kinematic tests of vector boson fusion using the ATLAS detector at the Large Hadron Collider

The first observation of electroweak W+jets production in the Vector Boson Fusion (VBF) topology using the ATLAS detector at the Large Hadron Collider (LHC) is presented. VBF probes the triple gauge vertex, a rare process that is validated in this measurement, and has begun to be explored in the Higgs sector. The signal in W boson production presented in this thesis is measured using proton-proton collisions at [special characters omitted] and 8 TeV at a statistical significance of greater than 5 standard deviations. Studies of the event kinematics are also presented via differential cross-section measurements as a function of various observables that are sensitive to VBF production. These are the first differential cross-section measurements for the VBF process. Results reflect the most precise measurements of electroweak and strong interactions in this kinematic domain. These measurements will serve as a reference point for related analyses using data at higher collision energies at the LHC. Results from this thesis will also contribute towards improving our theoretical understanding of the largest irreducible background in this analysis coming from strongly produced W+jets. Measurements presented, when representing potential backgrounds, will also be useful to studies of top quark and Higgs production, as well as new physics searches that deal with similar backgrounds.