Decay

Interactions are not the only things that can be observed in a bubble chamber. Sometimes a particle might decay after travelling some distance giving a characteristic signature which depends on its charge.

Decay of a charged particle

The sketch shows a typical charged (in this example positive) particle decay. A kink (sudden change in curvature) indicates the point at which the decay occurred. Notice the conservation of charge, indicated by the fact, that the direction of curvature is kept. As seen in the sketch, the proton does not take part in the decay process.

Decay of a neutral particle

The sketch shows a typical neutral particle decay. A "vee" (two tracks of opposite charge emerging from a point) indicates the location of  the decay. The incident particle is neutral (Q=0); the outgoing particles are oppositely charged (Q=1-1=0). As seen in the sketch, the proton does not take part in the decay process.