Effects of R-parity Violating Couplings on CP Asymmetries in Neutral B Decays

A detailed analysis of the effects of supersymmetric models without R-parity on various CP asymmetries in neutral $B$ decays is given. We concentrate on models with Abelian horizontal symmetries that allow us to estimate the order of magnitude of the new effects. We focus on channels where the Standard Model gives clean predictions: $ B_{d}\to\psi K_{S} $ and $B_{d}\to\phi K_{S}$. The two asymmetries can have a value different from $\sin2\beta.$ Moreover, they can be different from each other.