Effects of R-parity violation on direct CP violation in B decays and extraction of γ

Abstract

In the standard model, direct CP-violating asymmetries for B^± → π^±K are ∼2% based on perturbative calculation. Rescattering effects might enhance it to at most ∼(20–25)%. We show that lepton-number-violating couplings in supersymmetric models without R parity are capable of inducing as large as O(100%) CP asymmetry in this channel. Such effects drastically modify the allowed range of the Cabibbo-Kobayashi-Maskawa parameter γ arising from the combinations of the observed charged and neutral B decays in the πK modes. With a multichannel analysis in B decays, one can either discover this exciting new physics, or significantly improve the existing constraints on it.