Abstract:
This thesis tackles the problem of the nature of Dark Matter using two different
approaches: B-physics and neutrino-physics. A model independent strategy is implemented
to study B meson decays for evidence of WIMPs in FCNC processes.
The Wilson coefficients CDM responsible for transitions with dark matter scalars
are constrained using experimental bounds on different B meson decay processes
B ! M ; these bounds are also used to determine the phase space for the mass of
the dark matter candidate. Our results show that the decay processes with vector meson
final states prove more promising for studying due to the availability of a larger
phase space. Additionally, the applied constraints prefer smaller CDM values. Also,
the Majorana nature of neutrinos is probed using BSM extensions of the Krauss-
Nasri-Trodden model to study same-sign dilepton signatures ee ! `
`
+ Emiss
for the feasibility of detecting dark matter at current and future colliders. Analysis
performed on a selection of benchmarks obeying relic density, lepton flavour violation
and muon anomalous magnetic moment shows that a mass hierarchy is favoured
wherein MS2 < MS1 ; the constraints permit a larger number of benchmarks with
heavier dark matter candidates (MN1 ); in order to fulfil relic density and annihilation
cross-section bounds, the gi Yukawa couplings responsible for interactions of
N1, must be larger than the f couplings. A single benchmark is chosen for more
detailed study; a scan of the interaction cross sections for a range of ECM values
showed the minimum required energy for producing all channels is 400 GeV. The
cuts applied to various kinematic variables, for improving the visibility of the events
in excess of the SM events, are also discussed. The cuts and constraints help narrow
the favoured range for the mass of the dark matter Majorana neutrino candidate to
MN1 . 100 . 150 GeV. Additional methods for studying signal detectability and
improving the signal-to-noise ratio are briefly discussed.
