Roles of sterile neutrinos in particle physics and cosmology

Understand

The impacts of the light sterile neutrino hypothesis in particle physics and cosmology are reviewed.

• The observed short baseline neutrino anomalies challenging the standard explanation of neutrino oscillations within the framework of three active neutrinos are addressed.
• It is shown that they can be interpreted as the experimental hints pointing towards the existence of sterile neutrino at the eV scale.
• While the electron neutrino appearance and disappearance data are in favor of such a sterile neutrino, the muon disappearance data disfavor it, which gives rise to a strong appearance-disappearacne tension.