What are 'neutrino oscillations'?

Asked by: Robyn Soares

Answer

Neutrinos are members of the particle family called the Leptons. There are 6 leptons, the electron, the heavier muon, and the heavier still tau. Alongside them, each of the before mentioned particles has a neutrino associated with it, giving the electron-neutrino, the muon-neutrino and the tau-neutrino.

The sun releases a large number of neutrinos due to the nuclear reactions taking place in it, one neutrino for every proton that is converted to a neutron. Also, when lighter elements fuse to make heavier ones within the sun, neutrinos are also emitted. By monitoring the neutrino flux here on earth, we can study particle interactions within the sun and test our understanding of stellar physics.

However, all of the tests so far have detected far fewer neutrinos than expected, roughly one-third of the predicted amount. One theory for this is that neutrinos can undergo 'NEUTRINO OSCILLATIONS' and oscillate between the three identities, changing between electron-, muon-, and tau-neutrinos. As our detectors can only detect electron-neutrinos, this may explain why only one third of the predicted amount is detected.

For more info see: Discovery of neutrino mass and oscillations, the University of Hawaii paper.
Answered by: Simon Hooks, Physics A-Level Student, Gosport, UK