Neutrinos: A gateway to beyond the standard model
Abstract
The Standard Model (SM) of particle physics based on the gauge group $ SU(3) \otimes SU(2)_L \otimes U(1)_Y$ is very appealing as it describes physics at low energy quite spectacularly. However, it cannot be an ultimate theory of nature as both theoretical and experimental evidence implies new physics at high and low energy scales. For instance, it fails to describe several phenomena such as neutrino masses and mixings, the strong hierarchy in the masses of fermions, dark matter candidates, and the origin of the baryon asymmetry in the universe. Thus, a fundamental framework beyond the standard model (BSM) is needed to resolve the shortcomings of the SM. Constructing such BSM models to tackle these fundamental problems of the SM while being consistent with the existing low-energy data, focusing on explaining the neutrino masses and oscillations, is the primary goal of this dissertation. Several BSM models have been developed in this thesis to resolve the shortcomings of the SM, using applied group theory and quantum field theory. Furthermore, each model detailed out has its unique characteristics and several phenomenological consequences. Various neutrino mass models, in particular, are proposed to shed light on the unresolved puzzles of fundamental physics. Neutrinos can play an important role in particle physics, cosmology, and astrophysics: their properties have significant consequences on large-scale cosmological structures and the baryon asymmetry of the universe. On the other hand, cosmology put essential constraints on the neutrino mass making as a probe to test the proposed theories beyond the SM. This dissertation cast light on BSM physics with various neutrino mass models ranging from MeV scale to TeV scale new physics that can be tested at future colliders and neutrino experiments. For instance, it discusses the model of radiative neutrino masses at electroweak scale which also resolves anomalies reported in $B$-meson decays, $R_{D^{(\star)}}$ and $R_{K^{(\star)}}$, as well as in muon $g-2$ measurement, $\Delta a_\mu$. Moreover, models of radiative Majorana neutrino masses that require new scalars can also generate observable neutrino non-standard interactions (NSI) with the matter.
Collections
- OSU Dissertations [11222]