Dark Matter : No Place for WIMPs

The primary goal of this thesis will be to explore the `' of (WIMP) (DM), using simplified models in order to make some general statements on the allowed parameter space and to guide future detection efforts. The context for this thesis is a time in which many experiments are attempting, either directly or indirectly, to pin down the interactions of DM with the very precisely measured standard model. So far no robust signals have been found. Depending on your particular tastes, you may hold out for one particular realization of (BSM) physics (e.g. Supersymmetry) and explore its rich phenomenology to ever increasing precision. But as time marches on, with diminishing confidence in discovery despite concerted efforts, you may instead look for ways in which to explore all possible realizations at once, a approach, to help guide future searches and model building efforts. This is the utility of simplified models. We will show that much of the parameter space of a neutral thermal WIMP (with arbitrary spin, spanning a complete set of simplified models) is heavily constrained by a combination of indirect/direct searches. Inevitably, carrying out such a study requires many assumptions, not all of them sound all of the time. To test the robustness of the study we will take an in-depth phenomenological look at a more detailed model, tackling many of the assumptions of simplified models (such as minimal flavour violation and gauge-invariance). We will take several detours along the way. We will show that the next generation of direct detections machines will be sensitive detectors for light (sub GeV) new particles in the neutrino sector. We will also consider how heavy flavour observables might be impacted by the breakdown of the assumption of quark-hadron duality, rather than from genuine new physics.