Related papers: Sterile Neutrinos
Search for New Physics beyond the Standard Model is the main direction in particle physics nowadays. There are several experimental hints of New Physics. The most statistically significant (5-6$\sigma$) are the hints of eV mass scale…
There are $\sim3\sigma$ or more evidence of eV-scale sterile neutrinos from several different measurements. Many dedicated experiments are (being) created and (will) take data to confirm or refute the eV-scale sterile neutrinos. In this…
Lepton mixing, which requires physics beyond the Standard Model, is surprisingly compatible with a minimal, symmetryless and unbiased approach, called anarchy. This contrasts with highly involved flavor symmetry models. On the other hand,…
A simultaneous understanding of the results of the LSND experiment indicating $\nu_{\mu}-\nu_e$ oscillation together with other evidences for neutrino oscillations from solar and atmospheric neutrino data seems to require the existence of…
Joint analysis of the results of the Neutrino-4 experiment and the data of the GALLEX, SAGE and BEST experiments confirms the parameters of neutrino oscillations declared by the Neutrino-4 experiment $(\Delta m_{14}^2= 7.3 \text{eV}^2$ and…
Sterile neutrinos are SU(2) singlets that mix with active neutrinos via a mass matrix, its diagonalization leads to mass eigenstates that couple via standard model vertices. We study the cosmological production of heavy neutrinos via…
keV scale sterile neutrinos are excellent warm dark matter candidates. In the early Universe, these can be produced from oscillations and scatterings of active neutrinos. However, in the absence of any new physics, this mechanism is in…
The simplest model that can accomodate a viable nonbaryonic dark matter candidate is the standard electroweak theory with the addition of right-handed or sterile neutrinos. We reexamine this model and find that the sterile neutrinos can be…
The discovery of neutrino masses implies the existence of new particles, the sterile neutrinos. These particles can have important implications for cosmology and astrophysics. A sterile neutrino with mass of a few keV can account for the…
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…
A sterile neutrino in addition to the three known neutrinos seems unavoidable if one wants a simultaneous understanding of the results of the LSND experiment indicating $\nu_{\mu}-\nu_e$ oscillation together with other evidences for…
Sterile neutrinos are well-motivated and actively searched for new particles that would mix with the active neutrinos. We study their phenomenology when they are produced in the evaporation of early Universe black holes, a novel production…
We describe an extention of the Standard Model (the $\nu$MSM) by three light singlet Majorana fermions -- sterile neutrinos, which allows to address simultaneously the problem of neutrino oscillations and the problems of dark matter and…
A phenomenological model with active and sterile neutrinos is used for calculations of neutrino oscillation characteristics at the normal mass hierarchy of active neutrinos. Taking into account the contributions of sterile neutrinos,…
Light sterile neutrinos represent a well-motivated extension of the 3-neutrino paradigm. However, the impressive agreement between standard cosmology and data casts doubts on their existence. Here we present a class of scenarios that…
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…
We explore the range of parameters for dark-matter sterile neutrinos in an extention of the Minimal Standard Model by three singlet fermions with masses below the electroweak scale (the $\nu$MSM). This simple model can explain a wide range…
Sterile neutrinos with mass ~1 eV and order 10% mixing with active neutrinos have been proposed as a solution to anomalies in neutrino oscillation data, but are tightly constrained by cosmological limits. It was recently shown that these…
Sterile neutrinos are compelling dark matter (DM) candidates, yet the minimal production mechanism solely based on active ($\nu_a$)-sterile ($\nu_s$) oscillations is excluded by astrophysical observations. Non-standard self-interactions in…
Sterile neutrinos in the electronvolt mass range are hinted at by a number of terrestrial neutrino experiments. However, such neutrinos are highly incompatible with data from the Cosmic Microwave Background and large scale structure. This…