Study of rare B meson decays related to the CKM angle beta at BABAR.

摘要

This study reports measurements of the branching fractions of B meson decays to eta'K +, eta'K0, opi +, and oK0. Charge asymmetries are measured for the charged modes and the time-dependent CP-violation parameters S and C are measured for the neutral modes. The results are based on a data sample of 347 fb-1 containing 383 million BB¯ pairs recorded by the B ABAR detector at the PEP-II asymmetric-energy e+e- storage ring located at the Stanford Linear Accelerator Center.; Statistically significant signals are observed for all channels with the following results. B (B+ → eta' K+) = (70.0+/-1.5+/-2.8) x 10 -6, B (B0 → eta' K0) = (66.6+/-2.6+/-2.8) x 10 -6, B (B+ → opi+) = (6.7+/-0.5+/-0.4) x 10-6, B (B+ → oK +) = (6.3+/-0.5+/-0.3) x 10-6, and B (B0 → oK 0) = (5.6+/-0.8+/-0.3) x 10-6, where the first uncertainty is statistical and the second is systematic. We measure Ach (eta'K+ ) = +0.010+/-0.022+/-0.006, Ach (opi+) = -0.02+/-0.08+/-0.01, Ach (oK+) = -0.01+/-0.07+/-0.01, Sh'K0S = 0.56+/-0.12+/-0.02, Ch'K0S = -0.24 +/- 0.08 +/- 0.03, SwK0S = 0.62+0.25-0.29 +/-0.02 and CwK0S = 0.39+0.25-0.24 +/-0.03. The result in Sh'K0S contributes to the published measurement from BAB AR, which differs from zero by 5.5 standard deviations and is the first observation of mixing-induced CP-violation in a charmless B decay.