Observation of CP violation in B^0 -> eta' K^0 Decays

Abstract

We present measurements of the time-dependent CP-violation parameters S and C in B^0 --> eta' K^0 decays. The data sample corresponds to 384 million B Bar pairs produced by e^+ e^- annihilation at the Y(4S). The results are S = 0.58 +- 0.10 +- 0.03 and C = -0.16 +- 0.07 +- 0.03. We observe mixing-induced CP violation with a significance of 5.5 standard deviations in this b -> s penguin dominated mode.

7 pages, 2 postscript figures, resubmitted Phys. Rev. Letters in response to review. Fixed a typo in the caption of the figure 2 (B0bar instead of B0 and vice versa); in the same caption now we define the raw asymmetry