Electroweak Symmetry Breaking with a compact extra dimension

[Excerpt from the preface]: During my Ph.D. course, under the supervision of Riccardo Barbieri, I started working on Theoretical High Energy Physics. In particular I focused on the problem of Electroweak Symmetry Breaking and in this context I investigated the bene ts of introducing a compact extra dimension. In a series of papers, together with Riccardo Barbieri, Guido Marandella, Lawrence Hall, Yasunori Nomura, Takemichi Okui and Steven Oliver I built supersymmetric models in 5D and studied their phenomenology in detail [1, 2, 3, 4]. In this models Supersymmetry is broken by boundary conditions in the fth dimension and the ElectroWeak Symmetry Breaking is triggered by Supersymmetry breaking via the top/stop radiative corrections. The phenomenology of these models is signi cantly di erent than the one of the Minimal Supersymmetric Standard Model scenarios extensively studied in the literature. These papers constitute the subject of this Thesis and their results will be presented in the following Chapters.