This thesis describes in detail a search for weakly interacting massive particles as possible dark matter candidates, making use of so-called mono-jet events. It includes a detailed description of the run-1 system, important operational challenges, and the upgrade for run-2. The nature of dark matter, which accounts for roughly 25% of the energy-matter content of the universe, is one of the biggest open questions in fundamental science. The analysis is based on the full set of proton-proton collisions collected by the ATLAS experiment at the Large Hadron Collider at ¿s = 8 TeV. Special attention is given to the experimental challenges and analysis techniques, as well as the overall scientific context beyond particle physics. The results complement those of non-collider experiments and yield some of the strongest exclusion bounds on parameters of dark matter models by the end of the Large Hadron Collider run-1.

Nominated as an outstanding PhD thesis by the CERN, Geneva

Introduction.- Theory and Motivation.- The Standard Model of Particle Physics.- Dark Matter.- Proton-Proton Collisions.- Mono-Jet Events as Dark Matter Signature at Colliders.- Large Hadron Collider.- The ATLAS Experiment.- Operation of the Central Trigger during run-I.- Upgrade of the Central Trigger.- Analysis Strategy.- Data and Simulated Samples.- Physics Objects De¿nitions.- Event Selection.- Background Estimation.- Results and Interpretation.- Prospects with Future LHC DataConclusion.