Exploring the invisible Universe by Model building: Neutrinos and other Dark Matters

Abstract

The Standard Model (SM) of particle physics is a very successful, mathematically consistent and experimentally proven theory of the known elementary particles. However it is challenged by a variety of theoretical and experimental puzzles. Two well-established theoretical puzzles are the tiny neutrino masses generations and explaining the observed astronomical dark matter content of the Universe. Besides that there are a few anomalous experimental results that cannot be explained by the SM alone. These are the hints that we need some new physics beyond the SM. In this dissertation, we introduce new physics ideas in the form of a model at the MeV to TeV scale, by extending the SM by adding new particles and/or new gauge symmetry and study different puzzles of the SM. Since the new physics scale is below TeV, we can probe the models with the current data coming from various experiments.