Optimal Bounds on Heavy-Mediator Dark Matter

The aim of the thesis is to design a model-indepedent strategy for the interpretation of Dark Matter searches at colliders, using as reference the CMS mono-jet analysis of the data gathered by the detector in 2015. The strategy is based on the consistent usage of the Effective Field Theory (EFT) description of the Dark Matter signal that allows us to set bounds under the hypothesis that the Dark Matter interactions are due to the exchange of heavy mediator particles. Implementing it in a concrete experimental situations and assessing the expected limits requires a detailed study of the background and a refined simulation of the signal. Moreover, a new statistical procedure, based on the Shape Analysis method, is introduced in order to set universal bounds on heavy-mediator Dark Matter production at LHC. A comparison is performed between the performances of the new statistical method and those of a more traditional cut and count strategy. EFT limits can be reinterpreted in any specific underlying model.