B. Aubert, for the BABAR Collaboration
Published 2007-03-08, updated 2007-08-02Version 2
We report observations of CP violation in the decays B0 -> K+pi- and B0 -> pi+pi- in a sample of 383 million Y(4S) -> BBbar events. We find 4372 +/- 82 B0 -> K+pi- decays and measure the direct CP-violating charge asymmetry Akpi = -0.107 +/- 0.018 (stat) +0.007-0.004 (syst), which excludes the CP-conserving hypothesis with a significance of 5.5 standard deviations. In the same sample we find 1139 +/- 49 B0 -> pi+pi- decays and measure the CP-violating asymmetries Spipi = -0.60 +/- 0.11 (stat) +/- 0.03 (syst) and Cpipi = -0.21 +/- 0.09 (stat) +/- 0.02 (syst). CP conservation in B0 -> pi+pi- (Spipi=Cpipi=0) is excluded at a confidence level 1-C.L. = 8 * 10^{-8}, corresponding to 5.4 standard deviations.
Comments: 7 pages, 3 postscript figures, as published in Phys. Rev. Lett. (minor text changes)
Journal: Phys.Rev.Lett.99:021603,2007
Search for CP violation in the decay B0->D*+-D-+
Improved Measurement of CP Violation in Neutral B Decays to c cbar s
Search for CP violation in the decays $D^+_{(s)} \to K_S^0π^+$ and $D^+_{(s)} \to K_S^0K^+$
