particle splitting

[gib65]

It's called the J/psi particle (pause to look this up: two different discoverers' date=' one at Brookhaven, the other Stanford so I guess they named it differently) and is made up of a charm/anticharm quark pair, so it's a meson.

[/quote']

 

That's interesting. It means that the electron and positron are never "in" the J/psi particle. The J/psi particle starts out as a pair of quarks and then becomes an electron and a positron.

 

I'm quoting myself from this thread. The original question was what is an example of a particle that splits into two particles with opposite spin, and the answer, given by swansont, was that a J/psi particle will split into an electron and a positron with opposite spins. Then he added the above quote, which I found very interesting for the reason I mentioned. No one really took it from there, but I still find that interesting, so I'm starting a new thread on it.

 

So... it seems like the J/psi particle, which is composed of a charm/anticharm quark pair, transforms into an electron and a positron. Now, if I'm not mistaken, an electron is a fundamental particle (as far as we know). I'm not sure about positrons (although I would think they are since they're the equivalent to electrons except with opposite charge). I'm not sure if quarks are divisible into anything more fundamental either. So, conceivably (to me), these charm and anticharm quarks could be different arrangements of more fundamental particles (at least one of which would have to be an electron)which could be rearranged into a different order to give an electron and a positron. But I have my doubts that this is the case since I'm sure quarks and positrons are already fundamental (again, as far as we know). What this necessarily means is that when a particle splits into two or more particles, it's not necessarily "breaking apart" as it were, but "transforming" into something that wasn't there at all at the start.

 

Is this a plausible interpretation?

[swansont]

Yes, it is. The j/psi is quite massive — more than three times more than a proton, so there's a lot of energy available to create the other particle/antiparticle pairs.

[BenTheMan]

a better way to think about ``transforming'' is in terms of interractions with photons. So the j/psi is made of a charm and anti charm quark. They can annihilate to form a photon, which can then give an electron and a positron, or a muon and anti-muon, or even another j/psi particle:)

[gib65]

Isn't this stuff where string theory has its field day?

[Severian]

Not really. String theory doesn't have much to say about the [math]J/\psi[/math].

[gib65]

Not really. String theory doesn't have much to say about the [math]J/\psi[/math].

 

I thought they have a fancy way of explaining particle splitting. They would say that a particle, being a vibrating string loop, is able to split itself into two segments with different vibration frequencies each.