Measurements of branching fractions and CP asymmetries in hadronic B decays with η meson in the final state

We report measurements of two-body and three-body charmless hadronic B decays with at least one eta meson in the final state. These results are obtained from a 140 fb(-1) data sample collected at Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric energy e(+)e(-) collider. In B to pseudoscalar-pseudoscalar (PP) decays, we have observed B+ -> eta pi(+) and B+ -> K+ but no significant signals are found for neutral B meson decays. Significant signals are observed for the pseudoscalar-vector (PV) modes, B -> eta K* and B+ -> eta rho(+) with branching fractions larger than the pseudoscalar-pseudoscalar modes. Flavor specific CP violating asymmetries for the observed decays are also reported. Large signals are observed for the inclusive three-body decays with measured branching fractions B(B-0 -> eta K+pi(-)) = (33.4(-3.3)(+3.5) (stat)(-1.9)(+2.1)(syst)) x 10(-6) and B(B-0 -> eta pi(+)pi(-)) = (16.6(-3.2)(+3.5) (stat)(-1.0)(+1.4) (syst)) x 10(-6). Further study shows that the dominant contribution for B-0 -> eta K(+)pi(-) is the intermediate two-body states while in B-0 -> eta K(+)pi(-) the event topology is more phasespace like. We also search for the possible two-body decays, B-0 -> a(0)(-)K(+) and B-0 -> a(0)(-)pi(+). No signals are observed and upper limits at 90% confidence level are provided.