Why is the Strong Force Responsible for Pi+ + Proton -> K+ + X?

  • Context: Graduate 
  • Thread starter Thread starter zanyzoya
  • Start date Start date
  • Tags Tags
    Force Strong force
Join the discussion
Registration is free. Ask a follow-up in this thread, or start your own.
Sign up Log in
6 replies · 2K views
zanyzoya
Gold Member
Messages
14
Reaction score
0
Please can you help,
I have seen an exam question which asks which interaction is responsible for the following ...
Pi+ + proton >>>>> K+ + unknown particle X

The options for the answer include both the weak and the strong force. The actual answer is the strong force. What I would like to know is why the strong force is responsible rather than the weak force?
Many thanks
Zoya
 

Discussion

Physics news on Phys.org
Thanks for that. And am I right in thinking that either the strong or weak force could be responsible as only hadrons are involved, ie no leptons exist on either side of the equation? If there were leptons involved on either side then only the weak force could be responsible and not the strong?
 
for example in beta decay the weak force is responsible even though there are no leptons on the lhs and only on the rhs.
 
zanyzoya said:
Thanks for that. And am I right in thinking that either the strong or weak force could be responsible as only hadrons are involved, ie no leptons exist on either side of the equation? If there were leptons involved on either side then only the weak force could be responsible and not the strong?
That is one part of it, but the strong interactions also conserve many more things, such as quark flavor. There are generally several things to check. Of course, with X being an unknown particle you really cannot check quark flavor conservation.
 
Ah I see, thanks. Later on we are asked to find the strangeness of particle X. I guess strangeness wouldn't be conserved during the weak interaction and therefore you could not answer this question. Hence another reason the interaction must be due to the strong force.