# Forces involved in particle decays

1. Apr 12, 2010

### Cakey

Hey

I'm getting muddled deciding which forces are responsible in individual particle decays.

I'm looking at the hyperphysics page: http://hyperphysics.phy-astr.gsu.edu/hbase/forces/funfor.html

Here it says that the photon mediates the EM force. So does that mean that if photons are produced after a decay, the EM force was involved?

Then it says that the strong force is mediated by gluons and $$\pi$$ (nucleons), which I assume means pions(??). So if there are pions involved in a decay, the strong force must be involved?

I'm confused because I don't think it can be this straightforward, given that you get decays involving pions and photons.

Any advice would be very helpful ! Thanks!

2. Apr 12, 2010

### Norman

Did you read the rest of the information on that page?

When you say a particle "mediates" an interaction, you are talking about the virtual particle in the Feynman diagram. So, that does not necessarily mean it is in the end state of a decay. For instance, you will not see W and Z bosons in the final state of decays, but there are decays which proceed through the weak force (e.g. neutron and charged-pions).

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