论文标题
在先锋实验中测试Lepton风味普遍性和CKM Unitarity具有稀有乳头衰变
Testing Lepton Flavor Universality and CKM Unitarity with Rare Pion Decays in the PIONEER experiment
论文作者
论文摘要
描述了先驱实验的物理动机和概念设计，这是一种下一代稀有型腐烂实验测试Lepton风味普遍性和CKM Unitarity。 Paul Scherrer Institut提出和批准的先锋实验的第一阶段旨在测量与电子相对于电子的电荷分支比率，$ r_ {e/μ} $，比当前的实验结果高15倍，以达到标准模型（SM）的精确度（SM）在1 $ 10^4 $ 10^4 $ 10^4 $ $ 10^4 $中的精确度。考虑到SM预测和指向潜在违反Lepton风味普遍性的数据之间的几个不一致之处，先锋实验将通过对PEV质量量表的新粒子的量子效应的敏感性来探测这些异常的非SM解释。先驱实验的后期阶段旨在提高锥β衰减（BRPB）分支比的实验精确度，$π^+ \toπ^0 e^+ v+ v+ v+ v（γ）$，目前为$ 1.036（6）（6）\ times10^{ - 8} $，通过三（阶段II）和一个阶段III（阶段II）（II级）。 BRPB的这样的精确测量将允许根据CABIBBO角度异常进行CKM单位性测试，理论上最清洁的$ | v_ {Ud} | $在0.02 \％级的水平上，可与Superbolayed Beta衰减的扣除相当。
The physics motivation and the conceptual design of the PIONEER experiment, a next-generation rare pion decay experiment testing lepton flavor universality and CKM unitarity, are described. Phase I of the PIONEER experiment, which was proposed and approved at Paul Scherrer Institut, aims at measuring the charged-pion branching ratio to electrons vs.\ muons, $R_{e/μ}$, 15 times more precisely than the current experimental result, reaching the precision of the Standard Model (SM) prediction at 1 part in $10^4$. Considering several inconsistencies between the SM predictions and data pointing towards the potential violation of lepton flavor universality, the PIONEER experiment will probe non-SM explanations of these anomalies through sensitivity to quantum effects of new particles up to the PeV mass scale. The later phases of the PIONEER experiment aim at improving the experimental precision of the branching ratio of pion beta decay (BRPB), $π^+\to π^0 e^+ ν(γ)$, currently at $1.036(6)\times10^{-8}$, by a factor of three (Phase II) and an order of magnitude (Phase III). Such precise measurements of BRPB will allow for tests of CKM unitarity in light of the Cabibbo Angle Anomaly and the theoretically cleanest extraction of $|V_{ud}|$ at the 0.02\% level, comparable to the deduction from superallowed beta decays.
