Supersymmetry, Dark Matter and the Hierarchy of Yukawa Couplings

While the standard model successfully describes a wide array of phenomena amongthe fundamental particles and interactions, some significant problems remain. Theseinclude the hierarchy problem in the Higgs sector, the hierarchy of the Yukawa cou-plings, and the nature of dark matter. These problems are addressed in this thesis. First, the standard model and itsproblems are reviewed; supersymmetry is identified as possible framework for solvingall three problems. Second, brief reviews of supersymmetry and dark matter phe-nomenology are provided. Then, using gamma rays and neutrinos, novel astrophysi-cal constraints on the dark matter interpretation of the recently observed cosmic-raye± anomalies are developed. Finally, a class of supersymmetric models is describedwherein the first and second generation squarks and sleptons are pseudo-Nambu-Goldstone bosons, making their standard model counterparts naturally light, therebyresolving the Yukawa hierarchy problem. We show that this model an be easily iden-tified at the Large Hadron Collider after a few months of running at 14 TeV. Thisclass of models also provides a promising dark matter candidate which evades thederived gamma ray and neutrino bounds, and may be relevant to the cosmic ray e±anomalies in a certain parameter region