Tackling the dark matter problem: a phenomenologist’s perspective

In this thesis, we will approach the dark matter problem from several different directions. This work is developed from the point of view of a dark matter phenomenologist and as such it will involve both theory and experiments. We will first review the construction of the standard model and its problems. Among these problems, we focus our attention on the discussion of dark matter, revising the evidences, the candidates and the experiments currently looking for it. We proceed by building two original models with a good dark matter candidate: the mo- tivations for building the two models will be very different. First, we build a composite Higgs model driven by theoretical motivations. The construction of the model relies entirely on symmetry arguments, furthermore we have the possibility of solving more than one standard model problem at once. Then, we build a model where our dark matter candidate is accom- panied by a colored particle and the motivation for such a model is tied to the experiments. In this second model the focus will be on the prospects for detectability and study at LHC, more specifically on the interplay between different signatures. But this is not the end of the story. Finally, there is a third approach that is neither theoretical, nor experimental, but rather data-driven. Here we will try to investigate the possibility of finding dark matter by applying anomaly detection to the LHC data.