Measurement of B → K^∗(892)γ Branching Fractions and CP and Isospin Asymmetries

We present an analysis of the decays B⁰ → K^∗0(892)γ and B⁺ → K^∗+(892)γ using a sample of about 383 × 10⁶ BB events collected with the BABAR detector at the PEP-II asymmetric energy B factory. We measure the branching fractions B(B⁰ → K^∗0γ = (4.47 ± 0.10 ± 0.16) × 10^-5 and B(B⁺ → K^∗+ γ) = (4.22 ± 0.14 ± 0.16) × 10^-5. We constrain the direct CP asymmetry to be -0.033 < A(B → K^∗ γ) < 0.028 and the isospin asymmetry to be 0.017 < δ_0- < 0.116, where the limits are determined by the 90% confidence interval and include both the statistical and systematic uncertainties.