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在W玻色子的衰变中寻找重中性轻子,使用sqrt[s]=13 TeV pp中的迪勒普顿移位顶点与ATLAS探测器的碰撞
G Aad1, B Abbott2, D C Abbott3
1CPPM, Aix-Marseille Université, CNRS/IN2P3, Marseille, France.
Physical review letters
|August 25, 2023
概括
研究人员在大型强子对撞机 (LHC) 寻找重中性轻子 (N). 没有发现证据,为各种中微子模型设定了勒普顿混合参数的新限制.
科学领域:
- 粒子物理学 粒子物理学
- 高能物理 高能物理
- 碰撞器物理学 碰撞器物理学
背景情况:
- 粒子物理学的标准模型不包括重中性轻子.
- 中微子振荡实验表明,超越标准模型的新粒子存在.
- 寻找重中性轻子对于理解中微子质量和混合至关重要.
研究的目的:
- 为了寻找在质子对质子碰撞中产生的长寿命,重中性轻质子 (N).
- 设定重中性子和活性中微子之间的混合参数的限制.
- 探索单调和多调混合场景,考虑正常和反转的中微子质量层次结构.
主要方法:
- 分析了ATLAS探测器记录的sqrt(s) = 13 TeV pp碰撞的13 fb-1数据.
- 通过W→Nμ或W→Ne衰变产生的重中性子的重建.
- 使用重中性子的重建质量和位移的顶点信息,区分信号和背景事件.
主要成果:
- 没有观察到与重中性子的产生和衰变相一致的事件的显著过量.
- 在3GeV < mN < 15GeV范围内的重中性轻质子质的二次混合参数 (dU_{Nμ}dU2和dU_{Ne}dU2) 上设置了排除极限.
- 对于单味和多味混合场景设置了第一个极限,涵盖正常和反转的中微子质量层次结构.
结论:
- 信号的缺失限制了超越标准模型的理论,这些理论预测了重中性轻子.
- 这些结果为未来的搜索和理论模型提供了有价值的投入,旨在解释中微子特性.
- 这项研究有助于正在进行的努力,在能源前沿发现新的物理现象.
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