Study of B→ p pbar π π with Belle experiment

Kai-Ning Chu^1*, Min-Zu Wang¹

¹Physics, National Taiwan University, Taipei, Taiwan

* Presenter:Kai-Ning Chu, email:kainingchu@gmail.com

Using a data sample of 772×10⁶ BB pairs collected on the Υ(4S) resonance with the Belle detector at the KEKB asymmetric-energy e⁺e^- collider, we report the observations of B⁰→ p pbar π⁺π^- and B⁺ → p pbar π⁺π⁰. We measure a decay branching fraction of (0.83 ± 0.17 ± 0.17) × 10^-6 in B⁰ →p pbar π⁺π^- for M_ππ < 1.22 GeV/c² with a significance of 5.5 standard deviations. The contribution from B⁰ → p pbar K⁰ is excluded. We measure a decay branching fraction of (4.58 ± 1.17 ± 0.67) × 10^-6
for B⁺ → p pbar π⁺π⁰ with M_ππ < 1.3 GeV/c² with a significance of 5.4 standard deviations. We study the difference of the M_{p pbar} distributions in B⁰ → p pbar π⁺π^- and B⁺ → p pbar π⁺π⁰.

Keywords: Belle experiment, B meson physics , B baryonic decay, threshold enhancement