Effects ofR-parity violating couplings onCPasymmetries in neutralBdecays

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 could have a value different from $\sin2\beta.$ Moreover, they could be different from each other