Searches for sterile neutrinos at very short baseline reactor experiments

Understand

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 theoretical expectations in reactor experiments, and $\nu_e$ deficit in calibration runs with radioactive sources in the Ga solar neutrino experiments SAGE and GALEX.

• All three problems can be explained by the existence of sterile neutrinos with the mass square difference in the ballpark of $1~\mathrm{eV^2}$.
• Recently the MiniBooNE collaboration observed electron (anti)neutrino appearance in the muon (anti)neutrino beams.
• The significance of the effect reaches 6.0$\sigma$ level when combined with the LSND result.