Measurements of CP-violating Asymmetries and Branching Fractions in B Meson Decays to eta' K

TL;DR

This paper reports measurements of branching fractions and CP-violation parameters in B meson decays to eta' K, providing insights into CP violation and testing the Standard Model with data from 88.9 million BBbar pairs.

Contribution

First measurement of CP-violation parameters and branching fractions for B -> eta' K decays using a large data sample from e+e- collisions.

Findings

Branching fraction B(B+->eta'K+) = (76.9 +/- 3.5 +/- 4.4)*10^-6

Branching fraction B(B0->eta'K0) = (60.6 +/- 5.6 +/- 4.6)*10^-6

CP-violation parameters S = 0.02+/-0.34+/-0.03, C = 0.10+/-0.22+/-0.04

Abstract

We present measurements of the branching fractions of the decays B+ -> eta' K+ and B0 -> eta' K0. For B0 -> eta' K0s we also measure the time dependent CP-violation parameters S and C, and for B+ ->eta' K+ the time-integrated charge asymmetry Ach. The data sample corresponds to 88.9 million BBbar pairs produced by e+e- annihilation at the Upsillon(4S). The results are B(B+->eta'K+) = (76.9 +/- 3.5 +/- 4.4)*10^-6, B(B0->eta'K0) = (60.6 +/- 5.6 +/- 4.6)*10^-6, S = 0.02+/-0.34 +/- 0.03, C = 0.10+/-0.22 +/- 0.04, and Ach = 0.037 +/- 0.045+/- 0.011.