This picture comes from an experiment at CERN in which a beam of 8.2 GeV/c K- particles is fired into the 2 metre hydrogen-filled bubble chamber.
The main interaction produces 4 charged particles and a neutral particle that decays a little way downstream into two charged charged particles (with a characteristc `vee' shape).
This event is rich in the number of different particles that can be identified from a `reading' of the tracks: electron, positron, pi+, pi-, K0, , K-, mu +, mu-; for details.
In addition, one can infer the existence of various neutrinos in the decay of the pi+ (muon neutrino) and the mu+ (electron neutrino and antimuon neutrino).