We report inclusive and exclusive measurements for χc1 and χc2 production in B decays. We measure B(B → χc1X)= (3.03 ± 0.05(stat) ± 0.24(syst)) × 10−3 and B(B → χc2X)= (0.70 ± 0.06(stat) ± 0.10(syst)) × 10−3 . For the first time, χc2 production in exclusive B decays in the modes B 0 → χc2π −K+ and B + → χc2π +π −K+ has been observed, along with first evidence for the B + → χc2π +K0 S decay mode. For χc1 production, we report the first observation in the B + → χc1π +π −K+, B 0 → χc1π +π −K0 S and B 0 → χc1π 0π −K+ decay modes. Using these decay modes, we observe a difference in the production mechanism of χc2 in comparison to χc1 in B decays. In addition, we report searches for X(3872) and χc1(2P) in the B + → (χc1π +π −)K+ decay mode. The reported results use 772 × 106 BB events collected at the Υ(4S) resonance with the Belle detector at the KEKB asymmetric-energy e +e − collider.
Physical Review D
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