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# The decay of an Omega-Minus particle? watch

1. Particle physics is really doing my head in right now, I'm having issues understanding this question - "where is the weak interaction involved in the decay of an omega-minus particle?"

Can someone explain this to me? This topic just doesn't seem to agree with my head.
2. (Original post by Accalia)
Particle physics is really doing my head in right now, I'm having issues understanding this question - "where is the weak interaction involved in the decay of an omega-minus particle?"

Can someone explain this to me? This topic just doesn't seem to agree with my head.
The basic rules you need to work with are these:

1) Particles will always decay if there exists a lighter form for them to decay to;
2) Only the weak nuclear force does not obey conservation of quark flavour.

An omega minus has a quark content of three strange quarks. It is therefore the lightest baryon containing only second generation quarks, because the only lighter quarks are up and down, which are from the first generation. From this you know that the omega minus must decay via a weak process, as it will need to change one of it's strange quarks to an up or down quark - i.e. it will need to break quark flavour conservation. There's a bit more info here

I think therefore that the answer to your question would be something like 'the weak interaction is involved in the decay of the omega minus when one of the strange quarks it contains decays via a process that does not conserve strangeness'.
3. (Original post by Prime Suspect)
The basic rules you need to work with are these:

1) Particles will always decay if there exists a lighter form for them to decay to;
2) Only the weak nuclear force does not obey conservation of quark flavour.

An omega minus has a quark content of three strange quarks. It is therefore the lightest baryon containing only second generation quarks, because the only lighter quarks are up and down, which are from the first generation. From this you know that the omega minus must decay via a weak process, as it will need to change one of it's strange quarks to an up or down quark - i.e. it will need to break quark flavour conservation. There's a bit more info here

I think therefore that the answer to your question would be something like 'the weak interaction is involved in the decay of the omega minus when one of the strange quarks it contains decays via a process that does not conserve strangeness'.
Thank you I didn't realise it contained three strange quarks, seeing the steps for its decay really helped. Guess it teaches me not to attempt my homework without the data sheet.
4. (Original post by Accalia)
Thank you I didn't realise it contained three strange quarks, seeing the steps for its decay really helped. Guess it teaches me not to attempt my homework without the data sheet.
No worries, although for future reference I think it's pretty much impossible to do any particle physics question without knowledge of the particles the question is talking about! In short, make full use of the data sheet

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