Tau lepton facts for kids

Tau (τ) leptons, also called tauons, are incredibly tiny particles. Scientists believe they are so small that they cannot be divided into anything smaller. You can think of tau leptons as very heavy versions of electrons, because both are types of leptons. Tau leptons are about 3,500 times heavier than electrons. They are also about 17 times heavier than muons.

Tau leptons only exist for a tiny fraction of a second, about 0.00000000000029 seconds! Because they disappear so quickly, they don't play a big role in the everyday world around us. However, they are very important in how other super tiny particles break apart, a process called decay.

Like electrons and muons, tauons have their own special partner particle called a neutrino. For tauons, this partner is called the tau neutrino.

What Are Tau Leptons Like?

Tau leptons have an electric charge of -1. We write them as τ^–. Just like regular matter, there's also antimatter. The antimatter version of a tauon is called an anti-tauon. Anti-tauons have the opposite charge, so they have a charge of +1 and are written as τ⁺.

Tauons themselves are unstable, meaning they quickly break down or "decay." Also, a tauon (τ^–) and an anti-tauon (τ⁺) can meet and destroy each other in a process called annihilation.

How Do Tau Leptons Decay?

When a single tauon decays, it's special because it's the only type of lepton that can decay into hadrons. Hadrons are particles made up of even smaller particles called quarks.

Tauons (τ⁺ and τ^–) can be created when an electron and its antimatter partner, a positron (which is an anti-electron), combine. After they are formed, these two tauons then decay into other particles. They might turn into an electron and a positron, or a muon and an anti-muon. They also produce four different kinds of neutrinos.

However, a single tauon decays differently than when a tauon and an anti-tauon decay together.

Single Tauon Decay

A τ^– (tauon) quickly decays into a tau neutrino and another particle called a W boson. The W boson is also very unstable. It only exists for an even shorter time, about 0.0000000000000000000000003 seconds!

After that, the W boson decays into other particles. It can turn into:

• An electron and an electron antineutrino.
• A muon and a muon antineutrino.
• A down quark and an up antiquark.