Related papers: Can new generations explain neutrino masses?
We propose a novel theoretical understanding of neutrino masses and mixings, which is attributed to the intrinsic vector-like feature of the regularized Standard Model at short distances. We try to explain the smallness of Dirac neutrino…
Guided by the flipping principle, we propose a novel extension of the Standard Model based on a double right-handed $U(1)$ gauge symmetry. In this framework, all left-handed fermions are neutral, while right-handed fermions of the third…
We present the radiative corrections to neutrino masses in a minimal supersymmetric extension of the standard model with local $U(1)_{B-L}$ symmetry. At tree level, three tiny active neutrinos and two nearly massless sterile neutrinos can…
If three right-handed neutrinos are added to the Standard Model, then, for the three known generations, there are six quarks and six leptons. It is then natural to assume that the symmetry considerations that have been applied to the quark…
We consider phenomenologically allowed structures of the neutrino mass matrix in the case of three light neutrino species. Constraints from the solar, atmospheric and reactor neutrino experiments as well as those from the neutrinoless…
The discovery of neutrino oscillations invites many fundamental physics questions that have yet to be answered. Two of these questions are simple, easy to state, and essential: What are the values of the neutrino masses? Are neutrinos…
Many neutrino mass models postulate the existence of at least two extra fermions in order to account for the measured solar and atmospheric mass splittings. In these models, however, the predicted hierarchy between the two mass splittings…
Assuming that neutrinos are not Majorana fermions and the right handed Dirac neutrino does not exist, we propose a model in which the second and the third generations of the leptons are composites, while the first generation is fundamental.…
In this paper, it is shown that $N$naturalness scenarios share the intrinsic mechanism to suppress neutrino masses with other infrared neutrino mass models. In such models like extra-dimensional theories or many species theories, the large…
A minimal extension of the standard model to naturally generate small neutrino masses and provide a dark matter candidate is proposed. The dark matter particle is part of a new scalar doublet field that plays a crucial role in radiatively…
We study models in which neutrino masses are generated dynamically at cosmologically late times. Our study is purely phenomenological and parameterized in terms of three effective parameters characterizing the redshift of mass generation,…
Efforts to unify group-theoretically the standard-model gauge interactions with the generation structure of fermions and their mirror partners should be accompanied with the unification of the corresponding gauge couplings. In this paper…
In this paper we consider the possibility of neutrino mass varying during the evolution of the Universe and study its implications on leptogenesis. Specifically, we take the minimal seesaw model of neutrino masses and introduce a coupling…
We propose a realistic model with Majorana neutrinos in the framework of unifying the three generations of fermions by point interactions in an extra dimension. This model can simultaneously explain the origin of fermion generations,…
Non-observation of proton decays as well as the smallness of the neutrino masses can naturally be explained by the accidental baryon and lepton number symmetry in the Standard Model, where the approximate symmetries are a consequence of the…
We consider the minimal extension of the Standard Model with three generations of massive neutrinos that mix. We then determine the parameters of the model that satisfy all experimental constraints.
Naturally small neutrino masses can arise in some grand unified models. The mechanism of neutrino mass generation in these models typically requires the existence of neutral heavy leptons. We study the low-energy phenomenology of these new…
One puzzle of neutrino masses and mixings is that they do not exhibit the kind of strong "hierarchy" that is found for the quarks and charged leptons. Neutrino mass ratios and mixing angles are not small. A possible reason for this is…
Tiny neutrino masses can arise naturally via loop diagrams. After a brief review of the radiative mass generation mechanism, I present a new model wherein TeV scale leptoquark scalars induce neutrino masses via two--loop diagrams. This…
The various experiments on neutrino oscillation evidenced that neutrinos have indeed non-zero masses but cannot tell us the absolute neutrino mass scale. This scale of neutrino masses is very important for understanding the evolution and…