# Pi+ + p -> Sigma+ + pi+ + K0

1. Oct 6, 2011

### sj8100

pi+ + p --> Sigma+ + pi+ + K0

I have a simple question.
Could someone tell me the isospin is conserved in the above reaction? This is the way i understood this.

LHS possible Isospin values are 1/2, 3/2
RHS possible Isospin value is 5/2

5/2 is not in LHS. so, isospin is not conserved. Is this right. I am little confused here.

2. Oct 6, 2011

### clem

Re: pi+ + p --> Sigma+ + pi+ + K0

Ispins add like spins so the RHS has any Ispin from 1/2 to 5/2, but 5/2 is excluded by Ispin conservatiion.

3. Oct 6, 2011

Staff Emeritus
Re: pi+ + p --> Sigma+ + pi+ + K0

Hint: Look at the T3 component of isospin.

4. Oct 6, 2011

### clem

Re: pi+ + p --> Sigma+ + pi+ + K0

But that doesn't rule out I=5/2. Ispin conservation is needed for that.

5. Oct 6, 2011

Staff Emeritus
Re: pi+ + p --> Sigma+ + pi+ + K0

Look at the T3 components of both sides.

6. Oct 7, 2011

### clem

Re: pi+ + p --> Sigma+ + pi+ + K0

Oh, I got confused by the question and the k instead of k0bar.
Of course, T_3 shows it violates Ispin.
Even more strongly, it is Delta S=2.

7. Oct 7, 2011

### sj8100

Re: pi+ + p --> Sigma+ + pi+ + K0

Thanks for the replies. Things are clear to me now. thanks.