ISSN - 15507998, Physical Review D - Particles, Fields, Gravitation and Cosmology, 2006, vol. 74, p. -
Observation of B±→χc1π± and search for direct CP violation
We report the first observation of B±→χc1π±, a Cabibbo- and color-suppressed decay in a data sample of 386×106 BB̄ events collected at the Υ(4S) resonance with the Belle detector at the KEKB asymmetric-energy e+e- collider. We observe 55±10 signal events with a statistical significance of 6.3σ including systematic uncertainties. The measured branching fraction and charge-asymmetry is B(B±→χc1π ±)=(2.2±0.4±0.3)×10-5 and Aπ=0.07±0. 18±0.02, respectively. We also determine the ratio B(B±→χ c1π±)/B(B±→χc1K±)=(4.3±0.8±0.3)%. © 2006 The American Physical Society.