Licentiate thesis: The Inert Doublet Model - Indirect Dark Matter Detection & LEP II Limits
by
Erik Lundström(SU Fysikum)
→
Europe/Stockholm
FB53
FB53
Description
The Standard Model of particle physics provides an exceptionally precise description of our world on subatomic scales. Nevertheless there exist a number of indications for the need of new physics beyond it. One of them comes from the current concordance model of cosmology, in which dark matter i s key ingredient. While the dark matter has so far only revealed itself through the gravitational influence it exerts on its surroundings, there are good reasons to believe it is made up by WIMPs a hypothetical class of heavy elementary particles not encompassed by the Standard Model.
The Inert Doublet Model constitutes a phenomenologically interesting extension of the Standard Model Higgs sector. The model provides a new set of scalar particles, denoted inert scalars due to their lack of direct coupling to matter, of which the lightest is a WIMP dark matter candidate. Since only a handful of free parameters are introduced the main strength of the model can be said to lie in its simplicity.
In this thesis the phenomenology of the Inert Doublet Model is studied with focus on two aspects: the prospects for indirect detection of annihilating inert scalar dark matter, as well as the determination of bounds from the existing LEP II data.
It turns out that annihhilating inert scalar dark matter can give rise to extraordinary prominent monochromatic gamma-rays, something which can be searched for with the recently launched Fermi Gamma-ray Space Telescope. A detection of such a feature would unambiguously confirm the existence of particle dark matter.
Moreover, the absence of any excess above the expected Standard Model background within existing analyses of the LEP II accelerator data is used to constrain the Inert Doublet Model. Although it is found that a significant region of the parameter space can be excluded, many of the models providing good WIMP dark matter candidates remain valid.
