Neutrino oscillation experiments to search for sterile neutrinos

Abstract

Sterile neutrinos, which are neutral under the weak interaction, are new fermions beyond the standard model. Although experimental anomalies hinted at their existence, their interactions are still completely unknown, and they belong to the class of dark matter. On the other hand, they can mix with weak-interaction-active neutrinos, and their masses are assumed to be heavier than three generations of neutrinos, so their presence should be revealed in the form of probability oscillations with active neutrinos. We review various neutrino oscillation experiments that can verify the existence of light sterile neutrinos, focusing on the differences and the similarities between reactor neutrino experiments and accelerator neutrino experiments. The number of sterile neutrinos can be more than one. As a canonical approach, in this review, only the three-plus-one scheme is adopted to make prediction for future experiments. © 2016, Korean Physical Society. All rights reserved.