Radioactive source experiments in Borexino

Abstract

© Copyright owned by the author(s) under the terms of the Creative Commons Attribution-NonCommercial-ShareAlike Licence. Most of the neutrino oscillation results can be explained by the three-neutrino paradigm. However several anomalies in short baseline oscillation data (L/E of about 1 m/MeV) could be interpreted by invoking a light sterile neutrino. This new state would be separated from the standard neutrinos by a squared mass difference Δm 2new ∼ 0.1-1 eV 2 and would have mixing angles of sin 2 2θ ee ≳ 0.01 in the electron disappearance channel. This new neutrino, often called sterile, would not feel standard model interactions but mix with the others. We present the CeSOX and CrSOX projects to constrain the existence of eV-scale sterile neutrinos by deploying an intense radioactive β-source next to the Borexino detector