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测量 Λ_{b}^{0}→Λ(1520)μ^{+}μ^{-}差分支部分数的方法

R Aaij¹, A S W Abdelmotteleb², C Abellan Beteta³

¹Nikhef National Institute for Subatomic Physics, Amsterdam, Netherlands.

Physical review letters

|October 28, 2023

概括

第一次测量了罕见的Lambda_b^0到Lambda(1520) mu+mu-衰变的分支分数. 结果与理论预测在最大的Dumion质量平方间隔一致.

科学领域:

粒子物理学粒子物理学
高能物理高能物理
子光谱学子光谱学

背景情况:

美容 baryons 的罕见衰变提供了新物理学的敏感探测器.
以前对稀有衰变的测量表明与标准模型的紧张关系.
衰变Lambda_b^0 -> Lambda(1520) mu+mu-对新物理学的贡献非常敏感.

研究的目的:

第一次测量罕见衰变Lambda_b^0 -> Lambda(1520) mu+mu- 的分支分数.
为了测试标准模型对这种衰变的预测.
为了寻找新物理学的潜在迹象.

主要方法:

分析了由LHCb实验收集的大量数据集,其质量中心能量为7,8和13 TeV.
使用特定的动力学标准选择候选Lambda_b^0 -> Lambda(1520) mu+mu-衰变.
测量分支分数在不同间隔的dumion不变质量平方 (q^2),不包括charmonium共振.

主要成果:

第一次测量了Lambda_b^0 -> Lambda(1520) mu+mu-衰变的分支分数.
在最高的q^2区间 (q^2 > 15.0 GeV^2/c^4) 中测量的分支分数与标准模型的预测一致.
该协议为理论模型和潜在的新物理学贡献提供了有价值的约束.

结论:

报告了Lambda_b^0 -> Lambda(1520) mu+mu-分支分量的第一个测量.
结果与该地区的标准模型一致,理论不确定性最小.
这项研究有助于正在进行的努力,精确地探测标准模型,并在罕见的B-hadron衰变中寻找新物理.

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