# Particle Help

1. Sep 28, 2004

### rokket

I have a smal brain but am trying to help an elderly gentleman (who doesn't speak too good English) with his theories.

He talks about a "twon" or tuon in relation to the rapid deceleration of photons, producing eletron-positron pairs.

I can't find any particle or process similar to this except muons. Has anyone ever heard of twons?

2. Sep 28, 2004

Staff Emeritus
Maybe he means tauon; this is a heavy lepton in the same family as the electron. The three "flavors", from lightest to heaviest are electron, muon, tauon. The latter two names come from the greek letters mu and tau, used to designate those particles. Mu rhymes with moo, and tau rhymes with cow. Corresponding to each of these particles there is also a neutrino, called the electron neutrino, the mu-neutrino and the tau-neutrino.

3. Sep 28, 2004

### mathman

Pair production (mostly) occurs when a high energy (above 1.022 Mev) gamma ray passes close to a nucleus. Much more energy would be required to get muon or tau particles.

4. Sep 28, 2004

### marlon

Look, the twon is indeed tauon as sA pointed out... Now concerning the pair production, let me provide you with the "general" picture of this system works. In Quantum Field Theory or QFT (the theory that describes the socalled Standard Model in which all elementary particles are classified) the concept of a vacuum or the empty space is quite different from what we intuitively would call empty. The clue is that this vacuum-state is not really empty. It contains a gazillion socalled virtual particles that are on themselves not real, yet in some way (i won't get into this) they can influence real physical phenomena that we are able to observe by experiments...

So the vacuum state needs to be seen as a "sea" of virtual particles that can form virtual anti-particle pairs (also called the vacuum-fluctuations), a bit like bubbles in a bottle of water.These pairs are constantly created and they die very soon there-after.

Now suppose we can apply some energy to this vacuum state. What will be the consequence ? Well, some of these "vacuum-bubbles" can become real particles for a short time, just like an electron-positron-pair. This energy is used by the virtual particles to become real. Real, means in this case that a particle is the end-result of some interaction. A virtual particle will never be the "outcome" when for example some proton interacts with some electron.

So basically when enough energy is available some real particle can be created out of "nothing". The best example is probably the electron that is observed in beta-decay. It is an atomic nucleus that decays, yet an electron is observed. At first, scientists thought this electron came from the nucleus. Trust me, this is NOT the case. The explanation is that this electron is created out of nothing (the vacuum surrounding the nucleus) and the necessary energy is provided by the decaying mother-nucleus...

regards
marlon

5. Sep 29, 2004

### mathman

In the original question, the process involved a rapid deceleration of photons, producing electron-positron pairs. This means a real process, not the virtual processes of a vacuum.