Mixing induced CP violation in the decay B(d) ---> K0 anti-K0 within the standard model

Abstract Recently, flavour SU (3) symmetry of strong interactions has been combined with certain dynamical assumptions to derive triangle relations among B-meson decay-amplitudes. We show that these relations allow a prediction of the mixing-induced CP asymmetry A CPmix-ind ( B d →K 0 K 0 ). Contrary to statements made in several previous papers, this asymmetry should be non-vanishing in the Standard Model due to QCD-penguins with internal up- and charm-quark exchanges and could be as large as O (30%). The branching ratio BR ( B d →K 0 K 0 ) is expected to be of O (10−6). In the future, the results presented in this letter should allow interesting tests of the SU (3) triangle relations and of the Standard Model description of CP violation.