ISSN - 15507998, Physical Review D - Particles, Fields, Gravitation and Cosmology, 2005, vol. 71, p. 1-6
Measurements of branching fractions and CP asymmetries in B→ηh decays
We report measurements of B to pseudoscalar-pseudoscalar decays with at least one η meson in the final state using 140fb-1 of data collected by the Belle detector at KEKB e+e- collider. We observe the decay B+→ηπ+ and find evidence of B+→ηK+; the measured branching fractions are B(B+→ηπ+)=(4.8-0.7+0.8(stat)±0.3(sys))×10-6 and B(B+→ηK+)=(2.1±0.6(stat)±0.2(sys))×10-6. Their corresponding CP violating asymmetries are measured to be 0.07±0.15(stat) ±0.03(sys) for ηπ± and -0.49±0.31(stat)±0. 07(sys) for ηK±. No significant signals are found for neutral B→ηh decays. We report the following upper limits on branching fractions at the 90% confidence level: B(B0→ηK0)<2.0×10-6, B(B0→ηπ0)<2.5×10-6 and B(B0→ηη)<2. 0×10-6. © 2005 The American Physical Society.