B meson decays to charmless meson pairs containing eta or eta' mesons

TL;DR

This paper reports precise measurements of branching fractions and CP asymmetries in B meson decays to charmless meson pairs involving eta and eta' mesons, using the full BaBar dataset.

Contribution

It provides the first evidence for three B0 decay modes involving eta and omega mesons at greater than 3 sigma significance, with updated branching fraction and CP asymmetry measurements.

Findings

Evidence for B0→etaomega, eta'omega, and etaK0 decays at >3 sigma

Measured branching fractions for several B decay modes involving eta and eta'

Observed CP asymmetry in B+→etaK+ decay with a value of -0.36

Abstract

We present updated measurements of the branching fractions for B0 meson decays to etaK0, etaeta, etaphi, etaomega, eta'K0, eta'eta', eta'phi, and eta'omega, and branching fractions and CP-violating charge asymmetries for B+ decays to etapi+, etaK+, eta'pi+ and eta'K+. The data represent the full dataset of 467 10^{6} BB pairs collected with the BaBar detector at the PEP-II asymmetric-energy e+e- collider at the SLAC National Accelerator Laboratory. Besides large signals for the four charged B decay modes and for B0\to eta'K0, we find evidence for three B0 decay modes at greater than 3.0sigma significance. We find B(B0\to etaK0) = (1.15^{+0.43}_{-0.38} \pm0.09)x10^{-6}, B(B0\to etaomega) = (0.94^{+0.35}_{-0.30}\pm0.09)x10^{-6}, and B(B0\to eta'omega) = (1.01^{+0.46}_{-0.38}\pm0.09)x10^{-6}, where the first (second) uncertainty is statistical (systematic). For the B+\to etaK+ decay mode, we measure the charge asymmetry A_{ch}(B+\to etaK+) = -0.36 \pm 0.11 \pm 0.03.