Detector looks for specific decay
Scientists aim to use the Cuore detector to reveal a special type of radioactive decay – also known as neutrinoless double beta decay. If the decay occurs, it is proof that the neutrino is its own antiparticle. And if the tiny particle is just that, scientists have explained why the universe is full of matter and not only radiation from matter and antimatter that destroy each other. If the neutrino is its own antiparticle, other particles might also be, such as the heavy and energyrich particles that formed in the early universe. If so, the particles could decay into more matter than antimatter.
Ordinary beta decay
A neutron in the nucleus of an element decays into a proton, an electron, and a neutrino. So, the radioactive material changes into a new element that includes one more proton and one less neutron.
Double beta decay
Two neutrons decay into two protons, two electrons, and two neutrinos. Only a few isotopes – such as the tellurium isotope of
130Te – are double beta radioactive. They are not very radioactive, so the decay is very rare.
Neutrinoless double beta decay
Two neutrons decay into two electrons and two protons at the same time. The neutrinos should neutralise each other. So the decay can only take place, if the neutrino is its own antiparticle.