The B factory in KEK is the most intense electron-positron collider of the world with asymmetric energy input. We are examining the standard model and exploring new physics through studying rare decays and CP violation of B mesons mass-produced with the collider.

We are examining the quark model and searching new hadrons through studying B mesons mass-produced with the B factory. We are also exploring new physics through studying rare decays of tau leptons as the B factory can mass-produce them.