Related papers: Minimal Multi-Majoron Model
In this talk we discuss the implications of the Minimal Supersymmetric Standard Model augmented by a single U(1) anomalous family symmetry for neutrino masses and mixing angles. The left-handed neutrino states are provided with Majorana…
Models involving a U(2) flavor symmetry, or any of a number of its non-Abelian discrete subgroups, can explain the observed hierarchy of charged fermion masses and CKM angles. It is known that a large neutrino mixing angle connecting second…
In contrast to the original type I seesaw mechanism that requires right-handed Majorana neutrinos at energies much higher than the electroweak scale, the so-called low scale seesaw models allow lighter masses for the additional neutrinos.…
We explore the possibility of interpreting the solar and atmospheric neutrino data within the context of the Minimal Supersymmetric Standard Model augmented by a single U(1) anomalous family symmetry spontaneously broken by non-zero vacuum…
Motivated by effective low energy models of string origin, we discuss the neutrino masses and mixing within the context of the Minimal Supersymmetric Standard Model supplemented by a U(1) anomalous family symmetry and additional Higgs…
We discuss symmetries and scenarios leading to quasi-degenerate neutrinos in type-I seesaw models. The existence of degeneracy in the present approach is not linked to any specific structure for the Dirac neutrino Yukawa coupling matrix…
If neutrinos are to play a relevant cosmological role, they must be essentially degenerate with a mass matrix of the bimaximal mixing type. We study this scenario in the MSSM framework, finding that if neutrino masses are produced by a…
The recently announced Super-Kamiokande data on atmospheric neutrino oscillation seems to require a maximal mixing between the $\nu_{\mu}$ and $\nu_{\tau}$ within the conventional three neutrino picture. It is then tempting to suggest as…
Heavy right-handed neutrinos are highly motivated due to their connection with the origin of neutrino masses via the seesaw mechanism. If the right-handed neutrino Majorana mass is at or below the weak scale, direct experimental discovery…
The $\mu \nu$SSM proposes to use right-handed neutrino supermultiplets in order to generate the $\mu$ term and neutrino masses simultaneously. We discuss neutrino physics and the associated electroweak seesaw mechanism in this model. We…
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…
We construct a realistic model based on SUSY SO(10) with U(2) flavor symmetry. In contrast to the commonly used effective operator approach, $126-$dimensional Higgses are used to construct the Yukawa sector. R-parity symmetry is thus…
Motivated by the recent Super-Kamiokande experiment on atmospheric and solar neutrino oscillation we propose a see-saw model of three generations of neutrinos based on the gauge group $SU(2)_{L}\times U(1)_{Y}$ with discrete symmetries…
We present an analysis of normal and inverted hierarchical neutrino mass models within the framework of tri-bi-maximal (TBM) mixing. Considering the neutrinos to be quasi-degenerate (QDN), we study two different neutrino mass models with…
We study the mixing among different generations of massive neutrino fields in a $SU(2)_L \times SU(2)_R \times U(1)_Y$ gauge theory which includes Majorana and Dirac mass terms in the Yukawa sector. Parity can be spontaneously broken at a…
We implement a symmetry violation guideline into a two-Higgs-doublet model embedded with three right-handed neutrinos, and exploit the generic Yukawa structures of the model via a hypothetical symmetry restoration of a global…
We analyze a scenario where the right-handed neutrinos make part of a strongly coupled conformal field theory and acquire an anomalous dimension \gamma<1 at a large scale \Lambda. Their Yukawa couplings to the Higgs become irrelevant at the…
We present a minimal see-saw model based on an extension of the standard model (SM) which includes an additional U(1), with gauge charge $B - \frac{3}{2} (L_\mu + L_\tau)$. Requirement of anomaly cancellation implies the existence of two…
We assume the universal Yukawa coupling (democratic mass matrix) with small violations for quarks, charged leptons and neutrinos masses. We could reproduce the mass hierarchy for quark masses and V_{CKM} matrix elements precisely. We adopt…
Models with two right-handed neutrinos are able to accommodate solar and atmospheric neutrino oscillation observations as well as a mechanism for the baryon asymmetry of the universe. While economical in terms of the required new states…