The Belle II Experiment

The Detector



The new SuperKEKB accelerator and the large detector Belle II constitute a milestone in the investigation of the matter excess (CP violation) in the Universe.

In SuperKEKB, bunches of particles of matter (electrons) and their anti-particles (positrons), with energies up to 8 giga electron volts, are brought to collision at rates which are 40 times larger than in the previous KEKB accelerator. The particles being created in the collisions and the decay products formed are measured and analyzed in the Belle II experiment.
In the Belle II experiment, various detectors are arranged in cylindrical layers around the beam pipe, optimized to detect any of the decay products in the reaction. The decay products, such as electrons, muons, pions and other secondary particles can be measured precisely with these devices. The whole Belle II detector is approximately 10 meters wide, 10 meters high and weighs 1,500 tons altogether.
The major components of the Belle II detector are listed below.