Related papers: Neutrino Mass Models
We propose a simple model of the neutrino mass matrix which can explain the solar and atmospheric neutrino problems in a 3($\nu_L + \nu_R$) framework. Assuming that only two right-handed neutrinos are heavy and a Dirac mass matrix has a…
If the mixing angles in each of the seesaw sectors are all small, and the neutrino masses are hierarchical, we study the conditions for large neutrino mixing using triangular matrices. In particular, the implication of the neutrino…
We show how the seesaw mechanism for neutrino masses can be realized within a five dimensional (5D) warped geometry framework. Intermediate scale standard model (SM) singlet neutrino masses, needed to explain the atmospheric and solar…
Type I and type II seesaw contributions to the mass matrix of light neutrinos are inherently related if left-right symmetry is realized at high energy scales. We investigate implications of such a relation for the interpretation of neutrino…
Assuming a Zee-like matrix for the right-handed neutrino Majorana masses in the see-saw mechanism, one gets maximal mixing for vacuum solar oscillations, a very small value for $U_{e3}$ and an approximate degeneracy for the two lower…
It is often said that neutrino mass is a window to a new physics beyond the standard model (SM). This is certainly true if neutrinos are Majorana particles since the SM with Majorana neutrino mass is not a complete theory. The classical…
We study the neutrino mixing matrix (the MNS matrix) in the seesaw model. By assuming a large mass hierarchy for the heavy right-handed Majorana mass, we show that, in the diagonal Majorana base, the MNS matrix is determined by a unitary…
I discuss a class of hierarchical neutrino mass models based on the see-saw mechanism with single right-handed neutrino dominance. I apply this mechanism to a string inspired SUSY Pati-Salam model and indicate how it may emerge from…
A very simple extension of the standard model to include an Abelian family symmetry is able to describe the hierarchy of quark and lepton masses and their mixing angles together with the unification of gauge couplings. We consider the…
We consider the type I see-saw model with two right-handed neutrinos and a normal neutrino mass hierarchy and impose a zero coupling between the right-handed neutrino mainly responsible for the atmospheric neutrino mass and the electron…
Recent SNO results strongly favour the large mixing angle (LMA) MSW solar solution. We argue that there are only two technically natural low energy neutrino mass matrix structures consistent with the LMA MSW solution, corresponding to…
We propose a predictive lepton model under a modular $S_4$ symmetry, where the neutrino mass matrix arises from a radiative seesaw at one-loop level. The tree-level mass matrix is forbidden by well-assigned modular weights, which also play…
A model for neutrino masses and mixing is devised appointing the see-saw mechanism. The proffered model is fabricated with a combination of Type -I and Type-II see-saw contributions of which the latter dominates. The scalars and the leptons…
We consider several neutrino mass models in an extra-dimensional setting on a quantitative level. All the models are set in a five-dimensional scenario, with the standard model (SM) particles living on a brane, while three additional SM…
We introduce the idea of Form Dominance in the (type I) see-saw mechanism, according to which a particular right-handed neutrino mass eigenstate is associated with a particular physical neutrino mass eigenstate, leading to a form…
We suggest a hybrid seesaw model where relatively ``light''right-handed neutrinos give no contribution to the neutrino mass matrix due to a special symmetry. This allows their Yukawa couplings to the standard model particles to be…
We present a scenario of neutrino masses and mixing angles. Each generation includes a sterile right handed neutrino in addition to the usual left handed one. We assume a hierarchy in their Dirac masses similar to, but much larger than the…
The origin of neutrino mass is usually attributed to a seesaw mechanism, either through a heavy Majorana fermion singlet (version 1) or a heavy scalar triplet (version 2). Recently, the idea of using a heavy Majorana fermion triplet…
If neutrino masses are realized through the see-saw mechanism, can the right-handed neutrinos be produced and detected at present and future colliders? The answer is negative in the most popular see-saw scenarios for the simple reason that…
In the first part of the talk, three key ideas proposed in the 1970s, and in particular their combined role in providing an understanding of the neutrino-masses as well as of the baryon-asymmetry of the universe, are expounded. The ideas in…