Neutrinoless double beta decay is a very rare nuclear transition, whose existence can provide essential information about neutrino properties like the hierarchy and the absolute mass scale. If observed, this process will prove that the lepton number conservation law can be violated and that we need to extend the Standard Model.
T2K (Tokai to Kamioka) is the world leading experiment dedicated to the study of neutrino oscillations over a long distance using µ-neutrino and µ-anti-neutrino beams.
Neutrinos exist in three different types (called 'flavours'): νe, νμ and ντ. In the last fifteen to twenty years, several experiments have proven that neutrinos undergo a quantum mechanical phenomenon called 'oscillation', where neutrinos oscillate from one type to another.
