Enhancement of CP Violation in B^+- to K_i^+- D⁰ By Resonant Effects

Resonance width effects in charged $B$ decays to neutral $D$ mesons and excited kaon states $K_i$ around 1400 MeV are shown to lead to large calculable final state phases. $CP$ asymmetries are defined for any charged $B$ decay to three pseudoscalar mesons involving intermediate overlapping resonance states. Asymmetries up to about 10$\%$ are found in $B^+\to K^+_i D^0\to (K\pi)^+ D^0$. Decay distributions can be used to determine the weak phase $\gamma$ of the Cabibbo-Kobayashi-Maskawa (CKM) matrix. No separation of the contributions from individual resonances is required.