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arXiv · 0910.5817

Observation of B+ to p Lambdabar pi+ pi- at Belle

P. Chen·M. -Z. Wang
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Abstract

We study charmless $B^+$ meson decays to the $p \barΛ π^+ π^-$ final state using a $605 {\rm fb}^{-1}$ data sample collected at the $Υ(4S)$ resonance with the Belle detector at the KEKB asymmetric-energy $e^+ e^-$ collider. There are significant signals found with the $p\barΛ$ mass peaking near threshold. The observed branching fraction for non-resonant $ B^+ \to p \barΛ} π^+ π^-$ is $(5.92^{+0.88}_{-0.84} (stat.) \pm 0.69 (syst.)) \times 10^{-6}$ with a significance of 9.1 standard deviations. We also observe the intermediate three-body decay $B^+ \to p \barΛ ρ^0$ with a branching fraction of $(4.78^{+0.67}_{-0.64} (stat.) \pm 0.60 (syst.)) \times 10^{-6}$ and a significance of 9.5 standard deviations, and find a hint of a $B^+ \to p \barΛ f_2(1270)$ signal. No other intermediate three-body decay is found in this study.

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P. Chen, M. -Z. Wang. 2009-10-30. Observation of B+ to p Lambdabar pi+ pi- at Belle. https://doi.org/10.1103/physrevd.80.111103

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