Supersymmetry, dark matter and the hierarchy of Yukawa couplings

While the standard model successfully describes a wide array of phenomena among the fundamental particles and interactions, some significant problems remain. These include the hierarchy problem in the Higgs sector, the hierarchy of the Yukawa couplings, and the nature of dark matter.;These problems are addressed in this thesis. First, the standard model and its problems are reviewed; supersymmetry is identified as possible framework for solving all three problems. Second, brief reviews of supersymmetry and dark matter phenomenology are provided. Then, using gamma rays and neutrinos, novel astrophysical constraints on the dark matter interpretation of the recently observed cosmic-ray e+/- anomalies are developed. Finally, a class of supersymmetric models is described wherein the first and second generation squarks and sleptons are pseudo-Nambu-Goldstone bosons, making their standard model counterparts naturally light, thereby resolving the Yukawa hierarchy problem. We show that this model an be easily identified at the Large Hadron Collider after a few months of running at 14 TeV. This class of models also provides a promising dark matter candidate which evades the derived gamma ray and neutrino bounds, and may be relevant to the cosmic ray e+/- anomalies in a certain parameter region.