非参数且连续提取真实电弱企鹅衰变中的衰变振幅
Non-parametric and continuous extraction of amplitudes in realistic electroweak penguin decays
- MIT（麻省理工学院）
机构由 AI 辅助整理，请以论文原文为准。
AI总结：
提出一种模型无关方法，通过螺旋度角拟合和sPlot权重提取B介子衰变振幅，处理非因子化效率和本底，适用于真实实验数据，可提高对b→sℓℓ新物理的敏感性。
AI中文摘要：
最近提出了一种新方法，用于提取$B\to V(\to M_1M_2)\ell^+\ell^-$过程中的衰变振幅，其中$V$代表自旋$J=0$（S波）或$J=1$（P波）的介子。该方法通过对螺旋度角进行拟合，并随后计算sPlot权重，以模型无关的方式提取振幅对双强子和双缪子不变质量的依赖关系。在本文中，我们展示了当该方法应用于具有实验真实性的数据时，即存在探测效率和本底候选事件的情况下，仍能良好工作，其中探测效率和本底都可能对拟合的螺旋度角和提取的双粒子质量具有非因子化的依赖关系。我们证明，非因子化效率可以通过对传统sPlot权重计算进行小幅修改来适应，而非因子化本底则可以通过将本底分布的描述展开为各自因子化的项来处理。我们使用模拟的$B\to K^+\pi^-\mu^+\mu^-$数据来说明该方法，该数据包含$K^+\pi^-$系统中的S波和P波贡献，混合了非因子化本底候选事件，并使用真实的探测效率函数生成。我们还表明，该方法可以应用于比以前研究的更大的双缪子不变质量范围。这项工作表明，该方法适用于真实实验数据，可以提供模型无关的衰变振幅形状，以便与理论预测进行直接比较。使用该技术的测量可以提高对$b\to s\ell\ell$跃迁中潜在新物理效应的敏感性，并增进对强子形状因子的理解，特别是在S波系统中。
英文摘要：
A novel approach to extract decay amplitudes in $B\to V(\to M_1M_2)\ell^+\ell^-$ processes, where $V$ represents a meson with either $J = 0$ (S-wave) or $J = 1$ (P-wave), was recently proposed. In this method, the dependence of the amplitudes on the dihadron and dimuon invariant masses is extracted model-independently through a fit to the helicity angles and a subsequent calculation of sPlot weights. In this paper, we show that this method still performs well when applied to data with experimental realism, namely in the presence of detection efficiencies and background candidates, both of which can have non-factorising dependencies between the fitted helicity angles and extracted two-particle masses. We show that a non-factorising efficiency can be accommodated with a small change to the conventional calculation of the sPlot weights, and a non-factorising background by expanding the description of the background distribution into individually factorising terms. We illustrate the method using simulated $B\to K^+π^-μ^+μ^-$ data, containing both S- and P-wave contributions to the $K^+π^-$ system, mixed with non-factorising background candidates and generated with a realistic function for the detection efficiency. We also show that this method can be applied over a much larger dimuon invariant-mass range than studied previously. This work suggests that the method is suitable for application to real experimental data, where it could provide model-independent decay-amplitude shapes for direct comparison with theoretical predictions. A measurement using this technique can improve sensitivity to potential new-physics effects in $b\to s\ell\ell$ transitions, as well as the understanding of hadronic form factors, particularly in the S-wave system.
