This event shows an interaction of an 8.2 GeV/c K-
particle with a proton in the CERN 2 metre hydrogen bubble chamber.
The two outgoing charged particles are a proton and a pi minus.
The `vee' pointing back to the interaction is produced when
a neutral K0 produced in the original collision decays to a pi plus
and a pi minus.
The small curly tracks, curving anticlockwise, that can be seen on some
beam tracks are electrons which have been given a
small amount of energy by the beam particle. From their motion, it can
be seen that the magnetic field is out of the page (towards the reader).
For this event we have