# Threshold, proton-proton-collision

1. May 7, 2013

### Abigale

Hello,

I regard a proton-proton collision. (Target at rest.)
Here accrues a $K^{+}(494)$-meson.

I want to callculate the threshold energy.

But I think for callculating the threshold I have to know all participant of the product.
Can i assume, that the protons will not be destroyed?

$$p~+p~\rightarrow~p~+~p~+~K^{+}$$

(On the other hand I know, that for producing a $K^{+}$, which contains an $\bar{s}$-quark, due to strangeness-conservation, a proton must be replaced by an $\lambda(1116)$-hyperon, which contains an s-quark. )

THX
Abby

2. May 7, 2013

### Staff: Mentor

Baryon number is conserved, and the proton is the lightest baryon. With two protons in the final state (instead of hyperons), the process requires the weak interaction, it should be much more frequent with enough energy to do s sbar production.

3. May 18, 2013

### e.chaniotakis

Sorry, but the Kaon reaction you write doesn't conserve electric charge