| Description |
Dark matter is a prominent and dominant form of matter in the Universe. Yet, despite various intense efforts, its nongravitational effects have not been observed. In this dissertation, we explore the nature of such elusive particles within a supersymmetric SU(3)C ⊗ SU(2)L ⊗ U(1)Y gauge theory. Although large regions of parameter space within supersymmetric models have been excluded by recent results from collider experiments and direct and indirect dark matter searches, we find that there is a wide range of viable parameter space once the requirements of minimal flavor violation and mass universality are relaxed. In particular, we focus on a class of models in which electroweak-scale Majorana dark matter has interactions with the Standard Model sector via relatively light charged scalars with large chiral mixing and CP-violation. Our model is shown to lead to enhanced dark matter pair annihilation, and is constrained by precise measurements of the lepton dipole moments. We illustrate that our model satisfies all constraints, including the observed thermal relic density, and investigate prospects for the detection of dark matter annihilation products. We also examine the effects of chiral mixing and CP-violationn on the variation in the ratio of the flux of monoenergetic photons from annihilation to two photons relative to that from annihilation to a photon and a Z boson, as well as the helicity asymmetry in the diphoton final state. We also find the most general spectrum for internal bremsstrahlung, which interpolates between the regimes dominated by virtual internal bremsstrahlung and by final state radiation, and that it provides distinctive γ-ray signals, which could potentially be observed in the near future. |
