Q values for strong weak and EM interactions?

[philip041]

I have just read, in general, weak interactions, have the lowest Q values; meaning they have the smallest cross sections, which means they control processes in stars at some time in the early universe.

What would be the next relative strength?

Cheers

 

[malawi_glenn]

The Q-value just tells you how big phase space you'll have, the density of final states. Now there is more things that governs the cross section, the interaction matrix amplitude. And that is, the interaction itself, that turns the initial state into the final state.

 

[philip041]

Cheers, I think I am probably going to fail my exam, thanks anyway!