This is part of a picture taken in the CERN 2m hydrogen bubble chamber exposed to a beam of particles with a momentum of 10 GeV/c.
This comparatively simple event contains an example of one of the exotic particles of particle physics - the omega minus . The clue is to be seen in the topology of the tracks: the vee is pointing to the kink, not the primary interaction. (You can check this very easily by printing off the event and then following back - with a ruler - the line joining the point where the vee tracks cross to the vee decay point. It clearly points to the kink - click here)
The full reaction is
For more examples of omega minus click on one of the pictures below.