Related papers: Sterile Neutrinos in $E_{\rm 6}$
Sterile neutrinos of mass up to a few tens of TeV can saturate the present experimental bound of neutrinoless double beta decay process. Due to the updated nuclear matrix elements, the bound on mass and mixing angle is now improved by one…
We consider a four flavour scenario for the neutrinos where an extra sterile neutrino is introduced with the three families of active neutrinos and study the deviation from three flavour scenario in the ultra high energy (UHE) regime. We…
Sterile neutrinos comprise an entire class of dark matter models that, depending on their production mechanism, can be hot, warm, or cold dark matter. We simulate the Local Group and representative volumes of the Universe in a variety of…
Thanks to compelling evidence that neutrinos can change flavor, we now know that they have nonzero masses, and that leptons mix. In these lectures, we explain the physics of neutrino flavor change, both in vacuum and in matter. Then, we…
Sterile neutrino models with new gauge interactions in the sterile sector are phenomenologically interesting since they can lead to novel effects in neutrino oscillation experiments, in cosmology and in dark matter detectors, possibly even…
Current results of the MiniBooNE experiment show excess events that indicate neutrino oscillations, but only if one goes beyond the standard 3 family scenario. Recently a different explanation of the events has been given, not in terms of…
It is shown that it is possible to create successful models of flavor for both quarks and leptons using the discrete non-abelian group $T^{\prime}$ by itself. Two simple realizations are presented that can be used as the starting point for…
We propose a new and unique dark matter candidate: $\sim 100$ eV to $\sim 10$ keV sterile neutrinos produced via lepton number-driven resonant MSW (Mikheyev-Smirnov-Wolfenstein) conversion of active neutrinos. The requisite lepton number…
The sterile neutrino solutions to different irregular results and observations in neutrino physics are studied. It is pointed out that introducing sterile neutrinos helps to solve simultaneously the observed anomalies. It is argued that…
We analyze the oscillation signals generated by one extra sterile neutrino. We fully take into account the effects of the established oscillations among active neutrinos. We analyze the effects in solar, atmospheric, reactor and beam…
I point out that the sterile neutrinos suggested as candidates of "cool" Dark Matter will decay through their mixing with light neutrinos. This leads to an upper bound of about 200 keV on the mass of the sterile neutrinos, but might…
There is a great interest in measuring the non-electronic component of neutrinos from core collapse supernovae by observing, for the first time, also neutral-current reactions. In order to assess the physics potential of the ultra-pure…
Theoretical models which present flavor changing neutrino interactions and simultaneously prevent this particle from acquiring any mass exist. We discuss some of them and their predictions for neutrino oscillations in matter which can…
Light sterile neutrinos can be excited by oscillations with active neutrinos in the early universe. Their properties can be constrained by their contribution as extra-radiation, parameterized in terms of the effective number of neutrino…
We present numerical and comprehensive analyses of the sixty hybrid textures of neutrinos, which have an equality of matrix elements and one zero. These textures are possibly derived from the discrete symmetry. Only six textures among sixty…
If Nature has chosen the vacuum oscillation solution to the Solar neutrino puzzle, a key theoretical challenge is to understand the extreme smallness of the $\Delta m^2_{\nu_e-\nu_X}$ ($\sim 10^{-10} eV^2$) required for the purpose. We find…
We explore the possibility that the 3 active (doublet) neutrinos have nearly degenerate masses which are split only by the usual seesaw mechanism from 3 sterile (singlet) neutrinos in the presence of a softly broken $A_4$ symmetry. We take…
The question of whether the massive sterile neutrinos exist remains a crucial unresolved issue in both particle physics and cosmology. We explore the cosmological constraints on the massive sterile neutrinos using the latest observational…
We show that one can describe the quark and lepton masses with a single anomaly-free U(1) flavor symmetry provided a single order one parameter is enhanced by roughly 4-5. The flavor symmetry can be seen to arise from inside the $E_6$…
The recent measurement of high energy extragalactic neutrinos by the IceCube Collaboration has opened a new window to probe non-standard neutrino properties. Among other effects, sterile neutrino altered dispersion relations (ADRs) due to…