Particle Identification detectors allow using the information left by the particles passing through them, to identify the type of particle

A barrel-shaped array of Time-Of-Propagation (TOP) counters reconstructs in spacial and time coordinates, the ring-image of Cherenkov light cones emitted from charged particles passing through quartz radiator bars.

Another ring-imaging Cherenkov counters with aerogel radiator in the forward end-cap (A-RICH), is used to identify charged particles in the front-end endcap region of the Belle II spectrometer. Its main objective is to separate kaons from pions in the full kinematical region of the experiment (about 0.5-4.0 GeV).