# Some reaction between a proton and antiproton

1. Jun 20, 2007

### Ahmes

1. The problem statement, all variables and given/known data
Is the following reaction possible? If so, what is the type of interaction (EM, weak or strong)?
$$p+\bar{p}\rightarrow\pi^+ + \pi^- + \pi^0$$

2. Relevant equations
Conservation laws and rules of thumb regarding types of interactions.

3. The attempt at a solution
I don't think any conservation laws are broken so the process is possible. The question is how exactly. I don't have any idea how to put $\pi^0$ into Feynman diagrams... since its a superposition of two separate quark configurations. I drew the following:

If $\pi^0$ was just $u\bar{u}$ then my question would be whether only changing quark configuration means that it is a strong interaction. And if so, how to draw a Feynman diagram showing what really changed.
But $\pi^0$ is neither it nor $d\bar{d}$ - so what should I do?

Thanks!

2. Jun 20, 2007

### malawi_glenn

The $\pi^0$ is a superposition of $u\bar{u}$ and $d\bar{d}$, so $u\bar{u}$ do form a $\pi^0$.

3. Jun 21, 2007

### Meir Achuz

Allowed Strong Interaction