Measurement of The Time-Dependent CP Asymmetry in B0 --> K*0 gamma Decays

Understand

We present a preliminary measurement of the time-dependent CP asymmetry in B0 --> K*0 (K_S0 pi0) gamma decays based on 431 x 10^6 Upsilon(4S) --> BBbar decays collected with the BaBar detector at the PEP-II asymmetric-energy e+e- collider at SLAC.

• In a sample containing 316 +/- 22 signal events we measure S_{K* gamma} = -0.08 +/- 0.31 +/- 0.05 and C_{K* gamma} = -0.15 +/- 0.17 +/- 0.03.
• The uncertainties are statistical and systematic, respectively.