Sterile neutrino search at the ILL nuclear reactor: the STEREO experiment

Understand

Search for a light sterile neutrino is currently a hot topic of neutrino physics, arising from the so-called gallium and reactor anomalies, in which a deficit of neutrinos was observed with respect to expectations.

• Such anomalies could be explained by short distance oscillations towards a sterile state, with $\Delta \mathrm{m}^2\sim$1\,eV$^2$.
• The STEREO detector has been designed to track the electron anti-neutrino energy spectrum distortion from 3 to 8\,MeV due to such a new $L/E$ oscillation, and should therefore confirm or reject the light sterile neutrino hypothesis.
• Electron anti-neutrinos produced by the compact reactor core of the Institut Laue-Langevin (ILL) will be detected in a 6-cells segmented volume of Gd-loaded liquid scintillator through the inverse $\beta$-decay process.