Waiting for the discovery of $B^0_d\to K^0\bar K^0$

The CP asymmetries of the decay , which originates from flavor-changing neutral-current processes, and its CP-averaged branching ratio BR offer interesting avenues to explore flavor physics. We show that we may characterize this channel, within the standard model, in a theoretically clean manner through a surface in observable space. In order to extract the relevant information from BR , further information is required, which is provided by the system and the SU(3) flavor symmetry, where we include the leading factorizable SU(3)-breaking corrections and discuss how experimental insights into non-factorizable effects can be obtained. We point out that the standard model implies a lower bound for BR , which is very close to its current experimental upper bound, thereby suggesting that this decay should soon be observed. Moreover, we explore the implications for color suppression in the system, and convert the data for these modes in a peculiar standard-model pattern for the CP-violating observables.Received: 3 August 2004, Published online: 15 November 2004