Related papers: Sterile Neutrinos in $E_{\rm 6}$
In these brief lecture notes, we introduce sterile neutrinos as dark matter candidates. We discuss in particular their production via oscillations, their radiative decay, as well as possible observational signatures and constraints.
We revisit the flavor composition of high-energy astrophysical neutrinos observed at neutrino telescopes. Assuming unitary time evolution of the neutrino flavor states, the flavor composition observable at Earth is related to the initial…
A sterile neutrino is a well motivated minimal new physics model that leaves an imprint in neutrino oscillations. Over the last two decades, a number of hints pointing to a sterile neutrino have emerged, many of which are pointing near…
An algebraic argument based on a series of generalized Dirac equations, truncated by an "intrinsic Pauli principle", shows that there should exist two sterile neutrinos as well as three families of leptons and quarks. Then, the influence of…
Tantalizing cosmological and terrestrial evidence suggests the number of light neutrinos may be greater than 3, motivating a careful re-examination of cosmological bounds on extra light species. Big Bang Nucleosynthesis constrains the…
With the particle content of the 27 representation of E_6, a skew left-right supersymmetric gauge model was proposed many years ago, with a variety of interesting phenomenological implications. The neutrino sector of this model offers a…
Sterile neutrinos with various masses could be participated in astrophysical and cosmological processes including mixing with active neutrinos, if exist. It is considered the possible effects of mixing of active and sterile neutrinos with…
The interplay between neutrino masses and the interactions of neutrinos with matter is discussed with an eye to extending the latter to include possible new interactions. This conjecture may resolve the conundrum posed by the present…
We present a self--consistent $E_6$ inspired supersymmetric model with an extra $U(1)_{N}$ gauge symmetry under which right-handed neutrinos have zero charge. We explore the particle spectrum within the constrained version of this…
If the sterile neutrino mass matrix in an otherwise conventional see-saw model has a rank less than the number of flavors, it is possible to produce pseudo-Dirac neutrinos. For the rank 1 case, 3+2 scenarios devolve naturally, as we show by…
We consider field-theoretic models of a warped extra dimension with multiple throats, in which fermions that are singlets of the Standard Model gauge group propagate in a separate throat from the Standard Model fields, which we call the…
In several recent papers it was claimed that SN 1987A data supports the existence of 4.0 eV and 21.4 eV active neutrino mass eigenstates, and it was shown that such large masses could be made consistent with existing constraints including…
The recently measured unexpected neutrino mixing patterns have caused a resurgence of interest in the study of finite flavor groups with two- and three-dimensional irreducible representations. This paper details the mathematics of the two…
We delineate the maximal parameter space of sterile neutrino dark matter in the presence of lepton flavor asymmetries. We focus on large flavor asymmetries with vanishing total lepton asymmetry, which are washed out by neutrino oscillations…
If the hints for light sterile neutrinos from short-baseline anomalies are to be taken seriously, global fits indicate active-sterile mixings of a magnitude comparable to the known reactor mixing. We therefore study the conditions under…
The theory and phenomenology of neutrinos will be addressed, especially that relating to the observation of neutrino flavor transformations. The current status and implications for future experiments will be discussed with special emphasis…
Motivated by the recent observations on sterile neutrinos, we present a minimal extension of the canonical type-I seesaw by adding one extra singlet fermion. After the decoupling of right-handed neutrinos, an eV-scale mass eigenstate is…
Sterile neutrinos may be an important extension to the standard model, and could both hold the key to understanding neutrino mass and mixing as well as play an important role in leptogenesis. In many models, the sterile neutrinos could be…
A model, which extends the standard model with a new chiral U(1)$'$ gauge symmetry sector, for the eV-mass sterile neutrino is constructed. It is basically fixed by anomaly free conditions. The lightness of the sterile neutrino has a…
Significant evidence exists for the apparent disappearance of electron-type neutrinos in radioactive source experiments. Yet, interpreted within the standard `3+1 sterile neutrino scenario', precision short-baseline measurements of electron…