2 research outputs found
Study of B →p p ππ STUDY of B →p p ππ CHU K. et al.
© 2020 authors. Using a data sample of 772×106 BB pairs collected on the Ï\u27(4S) resonance with the Belle detector at the KEKB asymmetric energy e+e-collider, we report the observation of B0→ppπ+π- A nd the first observation of B+→ppπ+π0. We measure a decay branching fraction of (0.83±0.17±0.17)×10-6 in B0→ppπ+π-for Mπ+π-\u3c1.22 GeV/c2 with a significance of 5.5 standard deviations. The contribution from B0→ppK0 is excluded. We measure a decay branching fraction of (4.58±1.17±0.67)×10-6 for B+→ppπ+π0 with Mπ+π0\u3c1.3 GeV/c2 with a significance of 5.4 standard deviations. We study the difference of the Mpp distributions in B0→ppπ+π- A nd B+→ppπ+π0
Evidence for X (3872) →j/ψ π+ π-Produced in Single-Tag Two-Photon Interactions
We report the first evidence for X(3872) production in two-photon interactions by tagging either the electron or the positron in the final state, exploring the highly virtual photon region. The search is performed in e+e-→e+e-J/ψ π+ π-, using 825 fb-1 of data collected by the Belle detector operated at the KEKB e+e-collider. We observe three X(3872) candidates, where the expected background is 0.11±0.10 events, with a significance of 3.2σ. We obtain an estimated value for γB(X(3872)→J/ψ π+ π-) assuming the Q2 dependence predicted by a cc meson model, where-Q2 is the invariant mass squared of the virtual photon. No X(3915)→J/ψ π+ π-candidates are found