Related papers: Framework for Naturally Light Singlet Neutrinos
We give a pedagogical introduction to right-handed neutrinos as a simple extension to the Standard Model (SM), focussing on seesaw models and their possible experimental signatures. We preface this with a review of the lepton sector of the…
The three massless active (doublet) neutrinos may mix with two heavy and one \underline {light} sterile (singlet) neutrinos so that the induced masses and mixings among the former are able to explain the present data on atmospheric and…
It is well known that the differences between the lepton numbers can be gauged with the Standard Model matter content. Such extended gauge theories, dubbed as the gauged U(1)$_{L_\alpha - L_\beta}$ models, have been widely discussed so far…
We consider supersymmetric models in which the right-handed sneutrino is a viable WIMP dark matter candidate. These are either simple extensions of the Minimal Supersymmetric Standard Model or models with the addition of an extra U(1)…
We study the lepton sector in the model based on the local gauge group $SU(3)_c\otimes SU(3)_L\otimes U(1)_X$ which do not contain particles with exotic electric charges. The seesaw mechanism and discrete $A_4$ symmetry are introduced into…
We formulate a set of naturalness criteria for sterile neutrinos (\nu') to be light, needed for reconciling the LSND neutrino anomaly with the other neutrino data. A light sterile neutrino becomes as natural as the light active neutrinos if…
The smallness of the neutrino masses can be well understood within the seesaw mechanism. We analyse two cases of the minimal extension of the standard model when one or two right-handed fields are added to the three left-handed fields. A…
We consider the possibility to detect right-handed neutrinos, which are mostly singlets of the Standard Model gauge group, at future accelerators. Substantial mixing of these neutrinos with the active neutrinos requires a cancellation of…
We argue that the A_4 symmetry as required by three flavors of fermions may well-embed in the SU(3)_C X SU(3)_L X U(1)_X gauge model. The new neutral fermion singlets as introduced in a canonical seesaw mechanism can be combined with the…
Recently, it was shown in arXiv:1512.06742 that a straightforward implementation of the type I seesaw mechanism in a warped extra dimensional framework is in reality a {\em natural} realization of "inverse" seesaw, i.e., the Standard Model…
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…
Model-building issues raised by the prospect of light sterile neutrinos are discussed in a pedagogical way. I first review the na\"{\i}ve proposal that sterile neutrinos be identified with ``right handed neutrinos''. A critical discussion…
Massive neutrino is an evidence of new physics beyond the Standard Model. One of the well motivated new physics scenarios is a model with gauged lepton flavor symmetry. We investigate neutrino properties in the minimal…
We consider the supersymmetric seesaw mechanism induced by the exchange of heavy SU(2)_W triplet states, rather than `right-handed' neutrino singlets, to generate neutrino masses. We show that in this scenario the neutrino flavour structure…
We study the low scale predictions of supersymmetric standard model extended by $U(1)_{B-L}\times U(1)_{R}$ symmetry, obtained from $SO(10)$ breaking via a left-right supersymmetric model, imposing universal boundary conditions. Two singlet…
A beautiful understanding of the smallness of the neutrino masses may be obtained via the seesaw mechanism, whereby one takes advantage of the key qualitative distinction between the neutrinos and the other fermions: right-handed neutrinos…
We enlarge the lepton sector of the Standard Model by adding to it two right-handed neutrino singlets, and propose a model based on the seesaw mechanism and on the lepton number $\bar L = L_e - L_\mu - L_\tau$. The model is innovative from…
We make a general analysis of neutrino phenomenology for the case neutrino masses are generated by the see-saw mechanism with just two right handed neutrinos. We find general constraints on leptogenesis and lepton flavour violating…
We develop a class of left-right symmetric theories based on the gauge group $SU(3)_c \times SU(2)_L \times SU(2)_R \times U(1)$ with a generalized seesaw mechanism for generating the charged fermion masses. Neutrinos are naturally Dirac…
Various hints on the neutrino masses namely, ({\em i}) the solar neutrino deficit ({\em ii}) the atmospheric neutrino deficit ({\em iii}) the need for the dark matter and/or ({\em iv}) the non-zero neutrinoless double beta decay…