相关论文: Introduction to sterile neutrinos
Sterile neutrino dark matter is expected to suppress structure formation at small astrophysical scales. The details of the suppression depend on the sterile neutrino production mechanism in the early universe. In this proceeding, we focus…
We construct a family of simple gauge models in which three sterile neutrinos become naturally light by virtue of a generalized seesaw mechanism involving a chiral gauge symmetry. Examples where the chiral gauge group is SU(5)', SU(7)',…
For a long time there were 3 main experimental indications in favor of the existence of sterile neutrinos: $\bar{\nu_e}$ appearance in the $\bar{\nu_\mu}$ beam in the LSND experiment, $\bar{\nu_e}$ flux deficit in comparison with…
We propose a method to probe sterile neutrinos using polarization observables in the purely leptonic decays $\ell^{\prime-} \to \ell^{-} \bar{\nu}_{\ell} \nu_{\ell^{\prime}}$. By analyzing angular distributions and asymmetries derived from…
We study the phenomenology of a light (GeV scale) sterile neutrino sector and the pseudo-Goldstone boson (not the majoron) associated with a global symmetry in this sector that is broken at a high scale. Such scenarios can be motivated from…
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…
This white paper addresses the hypothesis of light sterile neutrinos based on recent anomalies observed in neutrino experiments and the latest astrophysical data.
The existence of two sterile neutrinos $\nu_s$ and $\nu'_s$ (blind to all Standard-Model interactions) is shown to be implied by a model of fermion "texture" that we develop since some time. They may mix nearly maximally with two of three…
Motivated by recent hints in particle physics and cosmology, we study the realization of eV-scale sterile neutrinos within both the seesaw mechanism and flavor symmetry theories. We show that light sterile neutrinos can rather easily be…
We provide a comprehensive study of observable spectra from dark matter pair-annihilation or decay into sterile (right-handed) neutrinos. This occurs, for instance, in neutrino portal dark matter models, where a sterile neutrino acts as the…
We investigate quantitatively the extent to which having a primordial leptonic asymmetry (n_nu \neq n_nubar) relaxes the bounds on light sterile neutrinos imposed by BBN and LSS. We adopt a few assumptions that allow us to solve the…
Several anomalies are discussed in neutrino physics, linked to the possible existence of light sterile neutrinos. These sterile neutrinos would not interact weakly, but they could leave an imprint in various measurements, such as neutrino…
Extending the Standard Model (SM) with sterile ('right-handed') neutrinos is one of the best motivated ways to account for the observed neutrino masses. We discuss the expected sensitivity of future lepton collider experiments for probing…
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 review the tensions with the standard three-neutrino framework for neutrino oscillation. These tensions hint at the possible existence of sterile neutrinos. We briefly describe some of the diverse ideas for probing the existence of such…
Neutrino oscillations present the only robust example of experimentally detected physics beyond the standard model. This review discusses the established and several hypothetical beyond standard models neutrino characteristics and their…
The role of the sterile neutrinos to the r-process nucleosynthesis in supernova explosions is studied. Previously it has been argued that a large part of neutrino mixing can be excluded if the supernovae are the origin of the heavy…
By numerically solving the appropriate Boltzmann equations, we study the production of sterile neutrinos in models with low reheating temperatures. We take into account the production in oscillations as well as in direct decays and compute…
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…
Light sterile neutrinos with a mass around 1 eV have been studied for many years as a possible explanation of the so called short-baseline neutrino oscillation anomalies. Recently, several neutrino oscillation experiments reported…