THE BELLE II EXPERIMENT

While B factories were built to check whether the Standard Model with the CKM matrix offers a correct description of CP violation, the next generation of B factories, super B factories, will look for departures from the Standard Model. For such a study, a 50 times larger data sample is needed, corresponding to an integrated luminosity of 50 ab(-1). To achieve the necessary increase of event rates by a factor of 40, a substantial upgrade is required both of the accelerator complex as well as of the detector. The motivation for a future super B factory at KEK and its expected physics reach will be discussed.