Supersymmetry, Dark Matter and the Hierarchy of Yukawa Couplings
- Author(s): Mandal, Sourav Kumar
- Advisor(s): Murayama, Hitoshi
- et al.
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 cou-
plings, 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 phe-
nomenology are provided. Then, using gamma rays and neutrinos, novel astrophysi-
cal 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 iden-
tified 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.