用強子標籤法研究含 Λ 終態的B 介子衰變

Abstract

本論文探討含 Λ 終態的帶電 B 介子衰變。利用來自日本高能加速 器研究機構 KEKB 之 Belle 偵測器在非對稱能量之電子正子對撞中 所產生的實驗數據分析，裡面含有 771 百萬來自 Υ(4S) 衰變的 B 介子對事件。分析方法採用以神經網路演算法為基礎的強子標籤法來 辨識其中一個 B 介子，再用剩餘的粒子重建 Λ/反Λ。 此實驗的結果以在對撞質心中 Λ/反Λ 的動量分佈呈現。

In this thesis, I report the study of inclusive charged B meson decay to Λ X, based on a data sample of about 772 million BBbar pairs collected with the Belle detector at KEKB asymmetric-energy e+e- collider at the Υ(4S) resonance. Events are selected by a fully reconstructed B meson using hadronic tagging method and then search for Λ baryons from the rest of the particles. The measured result is presented as inclusive momentum spectrum of Λ/anti-Λ particle in the e+e- center-of-mass frame.