Measurement of Branching Fractions and CP and Isospin Asymmetries in B -> K* gamma

TL;DR

This paper reports precise measurements of branching fractions, CP asymmetry, and isospin asymmetry in B meson decays to K* gamma using a large data sample from the BABAR experiment.

Contribution

First measurement of branching fractions, CP asymmetry, and isospin asymmetry in B -> K* gamma decays with high statistical significance.

Findings

Branching fraction BF(B0 -> K*0 gamma) = (4.58 +/- 0.11 +/- 0.16) x 10^-5

Branching fraction BF(B+ -> K*+ gamma) = (4.73 +/- 0.15 +/- 0.17) x 10^-5

CP asymmetry range: -0.043 to 0.025

Abstract

We present a preliminary analysis of the decays B0 -> K*0 gamma and B+ -> K*+ gamma using a sample of 383 x 10^6 BBbar events collected with the BABAR dector at the PEP-II asymmetric energy B factory. We measure the branching fractions BF(B0 -> K*0 Gamma) = (4.58 +/- 0.11 +/- 0.16) x 10^-5 and BF(B+ -> K*+ Gamma) = 4.73 +/- 0.15 +/- 0.17 x 10^-5. We measure the direct CP asymmetry to be -0.043 < A(B -> K* gamma) < 0.025 and the isospin asymmetry to be -0.021 < Delta0- < 0.079, where the limits are determined at the 90% confidence interval and include both the statistical and systematic uncertainties.