Related papers: Minimal See-Saw Model for Atmospheric and Solar Ne…
The atmospheric and solar neutrino oscillation data suggest hierarchical neutrino masses with at least one large mixing. The simplest see-saw models for reconciling the two features are U(1) extensions of the SM with flavour dependent gauge…
We have constructed an explicit see-saw model containing two singlet neutrinos, one carrying a $(B-3L_e)$ gauge charge with an intermediate mass scale of $\sim O(10^{10})$ GeV along with a sterile one near the GUT (grand unification theory)…
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 follow a minimalistic approach to neutrino masses, by introducing a single heavy singlet $N$ into the standard model (or supersymmetric standard model) with a heavy Majorana mass $M$, which couples as a single right-handed neutrino in a…
We discuss an extended SU(2)XU(1) model which naturally leads to mass scales and mixing angles relevant for understanding both the solar and atmospheric neutrino anomalies in terms of the vacuum oscillations of the three known neutrinos.…
The neutrino oscillations are studied in the framework of the minimal supersymmetric SO(10) model with Type-III see-saw mechanism by additionally introducing a number of SO(10) singlet neutrinos. The light Majorana neutrino mass matrix is…
The Standard Model augmented by the presence of gauge-singlet right-handed neutrinos proves to be an ideal scenario for accommodating nonzero neutrino masses. Among the new parameters of this ``New Standard Model'' are right-handed neutrino…
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…
The implementation of seesaw mechanisms to give mass to neutrinos in the presence of an anomaly-free U(1)_X gauge symmetry is discussed in the context of minimal extensions of the standard model. It is shown that type-I and type-III seesaw…
Neutrino oscillations data indicates that neutrino mixings are consistent with an apparent $\nu_\mu - \nu_\tau$ exchange symmetry in neutrino mass matrix. We observe that in the mininimally extended standard model with the see-saw…
Motivated by existing and recent data on possible neutrino oscillations, we propose a model of four light neutrinos ($\nu_e, \nu_\mu, \nu_\tau$, and a singlet $\nu_S$) with a pattern of masses and mixing derivable from a $Z_5$ discrete…
We propose models for neutrino masses and mixing in the framework of low scale $U(1)_{L_\mu-L_\tau}$ gauge extension of the standard model. The models are designed to spontaneously break $U(1)_{L_\mu-L_\tau}$ so that the…
We have investigated a neutrino mass matrix model without supersymmetry including three see-saw right-handed neutrinos around order $10^{12}$ GeV masses, aiming at a picture with all small numbers explained as being due to approximately…
We study models of neutrino masses which naturally give rise to an inverted mass hierarchy and bi-maximal mixing. The models are based on the see-saw mechanism with three right-handed neutrinos, which generates a single mass term of the…
We show that the assumption of type II seesaw mechanism for small neutrino masses coupled with $b-\tau$ mass unification in a minimal SUSY SO(10) model leads not only to a natural understanding of large atmospheric mixing angle…
We discuss an extended $SU(2)\times U(1)$ model which naturally leads to mass scales and mixing angles relevant for understanding both the solar and atmospheric neutrino anomalies. No right-handed neutrinos are introduced in the model.The…
The three electroweak doublet neutrinos $\nu_{e,\mu,\tau}$ of the Standard Model may acquire small seesaw masses, using either three Majorana fermion singlets $N$ or three Majorana fermion triplets $(\Sigma^+,\Sigma^0,\Sigma^-)$. It is…
We propose a new $\mathrm{SU}(3)_C \otimes \mathrm{SU}(2)_{L}\otimes \mathrm{U}(1)_{Y}\otimes \mathrm{U}(1)_{X}$ gauge model which is non universal respect to the three fermion families of the Standard Model. We introduce additional one…
This is a review article about neutrino mass models, particularly see-saw models involving three active neutrinos which are capable of describing both the atmospheric neutrino oscillation data, and the large mixing angle MSW solar solution,…
We study the simplest Standard Model estension with only one extra right-handed neutrino. In this case there are two massless $m_{1,2}$ and two massive $m_{3,4}$ neutrinos, and in principle both solar and atmospheric anomalies can be…