BESⅢ实上ψ(2S)→Ξ(1530)Ξ(1530)精确测量.pdf

文档介绍：BESIII 实验上ψ(2S) →Ξ(1530)Ξ̅(1530)精确测量中文摘要
BESIII 实验上𝛙(𝟐𝐒) →𝚵(1530)𝚵̅(1530)精确测量
中文摘要
本论文利用 BESIII 实验上累积的 ×108ψ(2S)衰变数据,详细研究了ψ(2S) →
Ξ(1530) Ξ̅(1530) 衰变过程。首次观测到ψ(2S) →Ξ 0(1530) Ξ̅ 0(1530) 和ψ(2S) →
Ξ-(1530)Ξ̅+(1530)衰变过程,精确测量出中性衰变道ψ(2S) →Ξ0(1530)Ξ̅0(1530)的衰变
分支比为( ± (stat.) ± (sys.)) × 10-5 , 也给出了带电衰变道ψ(2S) →
Ξ-(1530)Ξ̅+(1530)的衰变分支比为(±(stat.))×10-5,该测量结果为精确检验 QCD
理论提供了重要的实验信息。历史上 BESI 和 CLEO 实验组曾经测量过ψ(2S) →
Ξ0(1530)Ξ̅ 0(1530)中性衰变道,但是未观测到衰变事例,只是给出了分支比上限
×10-5,本论文以高达 9σ的显著性给出了精确的测量结果;对于该带电衰变道的研
究,本论文是世界上首次测量,并给出了精确的测量结果。

关键词:BESIII 实验;粲偶素衰变;重子;粒子物理实验



作者:魏晨阳
指导教师:徐新平王至勇许国发


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英文摘要 BESIII 实验上ψ(2S) →Ξ(1530)Ξ̅(1530)精确测量
Abstract
The decays of ψ(2S) →Ξ(1530)Ξ̅(1530) have been studied using the 106×106 ψ(2S)
events collected on BESIII experiment. The decays ψ(2S) →Ξ 0(1530)Ξ̅ 0(1530) and
ψ(2S) →Ξ-(1530)Ξ̅+(1530) are observed for the first time in the world. The branching
fraction ratio of ψ(2S) →Ξ 0(1530)Ξ̅ 0(1530) is measured to be (±(stat.)±
(sys.))×10-5. The branching fraction ratio of ψ(2S) →Ξ-(1530)Ξ̅+(1530) is measured
to be ( ± (stat.)) × 10-5. The measurements provide important experimental
information to test the QCD theory. The BESI and CLEO collaborations have investigated
the decay ψ(2S) →Ξ0(1530)Ξ̅0(1530), but no signal events are observed and the upper
limit ×10-5 is determined. In our measurements, the statistical significance of the signal
is larger than 9σ. The charged decay ψ(2S) →Ξ-(1530)Ξ̅+(1530) is observed for the first
time in the world and its branching fraction ratio is measured precisely.

Key Words: BESIII experiment; charmonium decay; baryon; particle physics
experiment



Written by Wei Chenyang
Supervised by Xu Xinping Wang Zhiyong Xu Guofa

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目录
中文摘要................................................................................................................................ I
Abstract ................