An antiproton enters from the top, annihilating with a proton in the Saclay/Ecole Polytechnique, Paris 81 cm liquid hydrogen bubble chamber

In the annihilation a $K^{0}$, $K^{-}$ and $\pi^{+}$ are produced in A as well as a $\pi^{0}$ which is found by the kinematic analysis of the event. The $K^{0}$ decays in B into $\pi{+} + \pi^{-}$ , the $\pi^{+}$ decays in C, giving $\mu^{+} \nu$. , and the $\mu^{+}$ decays at D into $e^{+} + \nu + \nu$. The $K^{-}$ interacts in E, giving $\Lambda^{0}$ and a $\pi^{0}$. The $\Lambda^{0}$ decays in F into a proton, which stops in G, and a $\pi^{-}$. The $\pi^{0}$ is not seen. The $\pi^{+}$ produced in A scatters on a proton in H.