衡量分支分量的比率R(D^{*}) 和R(D^{0})
R Aaij1, A S W Abdelmotteleb2, C Abellan Beteta3
1Nikhef National Institute for Subatomic Physics, Amsterdam, Netherlands.
Physical review letters
|September 29, 2023
概括
研究人员测量了涉及陶和子子的B介质子衰变的比率. 结果显示与标准模型略有偏差.
科学领域:
- 高能物理 高能物理
- 粒子物理学 粒子物理学
- 味道物理学的物理
背景情况:
- 粒子物理学的标准模型 (SM) 预测了子风味的普遍性,这意味着不同类型的子 (电子,子,陶) 在弱相互作用中应该表现相同.
- 之前的实验结果已经暗示了B质子衰变中pton风味普遍性的潜在违规,这表明了超越SM的可能的新物理学.
研究的目的:
- 测量分支分数R(D*) 和R(D0) 的比率,用于B质子分解为tau和子子.
- 为了测试B质子衰变中的勒普顿风味的普遍性.
- 为正在进行的B介质子衰变异常调查提供精确的测量.
主要方法:
- 利用LHCb实验记录的来自质子对质子碰撞的3.0fb^{-1}数据样本.
- 通过它们的衰变模式识别了陶氏子到子和中微子.
- 假设同脊柱对称性来关联不同的衰变通道.
主要成果:
- 测量R ((D*) = 0.281 ± 0.018 (国家统计) ± 0.024 (系统).
- 测量的R (D0) = 0.441 ± 0.060 (统计) ± 0.066 (系统).
- 结果与以前的测量结果一致,但显示了SM预测勒普顿风味普遍性的1.9标准偏差的综合偏差.
结论:
- 测量的比值R(D*) 和R(D0) 提供了关于B介质子衰变中的勒普顿风味普遍性的进一步数据.
- 虽然没有达到确定的新物理学值,但结果与标准模型预测保持了紧张关系.
- 持续精确的测量对于解决潜在的差异和探索新的物理场景至关重要.
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