无魅力的巴里昂衰变B^{+}→Λ[超过 ̄]pp[超过 ̄]p的第一次观测
R Aaij1, A S W Abdelmotteleb2, C Abellan Beteta3
1Nikhef National Institute for Subatomic Physics, Amsterdam, Netherlands.
Physical review letters
|January 20, 2026
概括
研究人员首次测量了无魅力的重子衰变B+到Lambda-bar p p-bar p的分支分数. 这项研究为LHCb实验中的罕见B+衰变和粒子物理学提供了新的见解.
科学领域:
- 粒子物理学 粒子物理学
- 高能物理 高能物理
- 实验物理实验物理学
背景情况:
- 该研究的重点是B+中子的无魅力的重子衰变.
- 了解这些衰变对于测试粒子物理学的标准模型至关重要.
研究的目的:
- 为了寻找和描述无魅力的重子衰变B+ -> 兰巴巴 p p-bar p.
- 为了第一次测量它的分支分数和CP不对称性.
主要方法:
- 来自LHCb实验的质子-质子碰撞数据的分析.
- 与正常化通道 (B+ -> J/psi K+) 相对的分支分数的测量.
主要成果:
- 分支分数B ((B+ -> Lambda-bar p p-bar p) 的测量结果是 (2.15 ± 0.35 ± 0.12 ± 0.28) x 10^-7.
- 测定CP不对称性为A_CP = (5.4 ± 15.6 ± 2.4)%.
- 不变质量分布显示在动力学值的增强.
结论:
- 这是第一次测量这个衰变的分支分数.
- 在质量分布中观察到的特征需要进一步进行理论研究.
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