Precision Tests of Flavor and CP violation in B Decays

Abstract

Isospin and flavor SU(3) set stringent bounds on penguin pollution in $B^0(t)\to {\rho }^{+}{\rho }^{-}$, providing a theoretically precise determination of $\alpha \equiv {\varphi }_2$, $\alpha =(91\pm 7_{\exp }\pm 3_{\mathrm{th}}{)}^{\circ }$. Isospin breaking in a sum rule for $B\to K\pi$ rates is shown to be suppressed. A similar sum rule holds for CP asymmetries in $B\to K\pi$. Violation of these sum rules would be evidence for an anomalous $\Delta I=1$ piece in ${\mathcal{H}}_{\mathrm{eff}}$.

Comments: Reference added; Invited talk presented at the First Workshop on Theory, Phenomenology and Experiments in Heavy Flavor Physics, Anacapri, Italy, 29-31 2006