Neutrino

Key Stage 5

Neutrinos are neutral leptons with negligible mass.

The neutrino is denoted with the Greek letter ν ('nu').

Neutrinos are very difficult to detect but they have been demonstrated to exist due to the law of conservation of momentum applied during decay occurring due to the weak interaction. During a decay the observable products can be seen to move in such a way as would violate conservation of momentum showing that another subatomic particle must be created in the decay.

Due to their negligible mass, neutrinos are very stable and pass through most matter without any interaction.

Neutrinos released during decay tend to travel at speeds approaching the speed of light.

The evidence for neutrinos also reveals the conservation of lepton number.