Precision Tests of Flavor and CP Violation in B Decays

Isospin and flavor SU(3) set stringent bounds on penguin pollution in B0(t)→ρ+ρ−, providing a theoretically precise determination of α≡ϕ2, α=°(91±7exp±3th). Isospin breaking in a sum rule for B→Kπ rates is shown to be suppressed. A similar sum rule holds for CP asymmetries in B→Kπ. Violation of these sum rules would be evidence for an anomalous ΔI=1 piece in Heff.