在 Belle 實驗中尋找 B0 介子衰變至 X(3872) γ 之分析

Abstract

本篇論文在 Belle 實驗中尋找 B0 → X(3872)(→ J/ψ π+ π−)γ 之衰變。分析數據來自日本高能加速器研究機構 B 介子工廠（KEKB）在能量不對稱之正負電子對撞器中所蒐集，來自 Υ(4S) 衰變的 772 百萬 BB ̄ 介子對，其積分亮度為 711 fb^−1。本篇論文量測結果中並沒有發現顯著性的訊號，並得到了 90% 信心水準之下的衰變分支上限值為 B(B0 → X(3872) γ) × B(X(3872) → J/ψ π+ π−) < 5.1 × 10^−7。

We report the results of a search for the decay B0 → X(3872)(→ J/ψ π+ π−)γ. The analysis is performed on a data sample corresponding to an integrated luminosity of 711 fb^−1 and containing 772 × 10^6 BB ̄ pairs, collected with the Belle detector at the KEKB asymmetric-energy e+e- collider running at the Υ(4S) resonance energy. We find no evidence for a signal and place an upper limit of B(B0 → X(3872) γ) × B(X(3872) → J/ψ π+ π−) < 5.1 × 10^−7 at 90% confidence level.