Subatomic particles and forces:
Discovering Neutrino Oscillation
Note: Units 1 through 3 make use of this interactive lab to demonstrate concepts relevant to physics on a subatomic scale.
Neutrinos are three of the twelve fundamental fermions of the Standard Model. These three particles are usually referred to by their flavor, electron, muon, and tau. These particles were originally thought to be massless, but now we know that neutrinos do in fact have very small masses. Exactly what the masses are is still an active area of research, but scientists realize that the neutrinos' ability to morph from one flavor to another is related to the mass differences between the three particles. The physics governing neutrinos is a fascinating particle physics mystery and also of practical interest. Neutrinos are produced in nuclear reactions and can travel through solid Earth with little attenuation. Therefore, one application of neutrino detectors might be to monitor nuclear reactors as part of a nonproliferation effort.