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在衰变中搜索 Λ[over ̄]-Λ baryons-number-violating 振荡 J/ψ→pK^{-}Λ[over ̄]+c.cc
M Ablikim1, M N Achasov2, P Adlarson3
1Institute of High Energy Physics, Beijing 100049, People's Republic of China.
Physical review letters
|October 6, 2023
概括
研究人员在J/ψ衰变中寻找超子振荡,但没有发现 Λ[over ̄] 到 Λ 过渡的证据. 这项研究为振荡速率设定了新的极限,为我们对基本粒子物理学的理解做出了贡献.
科学领域:
- 粒子物理学 粒子物理学
- 高能物理 高能物理
- 量子力学就是量子力学.
背景情况:
- 粒子物理学的标准模型描述了基本粒子和力.
- 超子,如兰巴达 (Λ) 和反兰巴达 (Λ[over ̄]),是含有奇怪夸克的子.
- 物质和反物质粒子之间的振荡的可能性,如 Λ 和 Λ[over ̄],是研究的一个关键领域.
研究的目的:
- 进行第一个对 Λ[over ̄]-Λ 振荡的搜索.
- 为了分析衰变J/ψ → pK−Λ[over ̄] + c.c.c. 对于这些振荡的证据.
- 为振荡率和参数设置极限.
主要方法:
- 通过BESIII探测器收集的1.31×109 J/ψ事件的分析.
- 使用J/ψ事件产生的e+e−碰撞在3.097GeV的质量中心能量.
- 统计分析以寻找振荡信号并设置上限.
主要成果:
- 在分析的J/ψ衰变中没有观察到 Λ[over ̄]-Λ振荡的证据.
- 振荡速率P(Λ的上限被确定为小于4.4×10−6.
- 在90%的置信级别下,振荡参数 δm_{ΛΛ[over ̄]} 的上限被设定为小于3.8×10−18 GeV.
结论:
- 搜索没有发现任何关于hyperon振荡的迹象.
- 结果为 Λ[over ̄]-Λ 振荡现象提供了严格的约束.
- 这项研究有助于持续探索粒子物理中的CP违规和物质-反物质不对称性.
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