标题： $b \rightarrow s\bar{\ell} \ell$衰变中短距离动力学的新测试 显示英文标题

标题： New tests of short-distance dynamics in $b \rightarrow s\bar{\ell} \ell$ decays

摘要： 稀有的$B \to K^{(*)} \bar{\ell} \ell$衰变表现出与标准模型（SM）预测长期存在的矛盾，这可以归因于一种轻子普遍的短距离$b \to s \bar{\ell} \ell$相互作用。 我们提出了两种新方法，以将这种效应与长距离动力学区分开来：一种是基于在高双轻子不变质量（$q^2\geq 15~{\rm GeV}^2$）下确定包含性$b \to s \bar{\ell} \ell$率，另一种是基于对独特色谱的分析，即对独占模式$B \to K^{(*)} \bar{\ell} \ell$的$q^2$谱（在整个$q^2$范围内）。 使用第一种方法，我们证明了在高双轻子不变质量下，标准模型对包含性$b \to s \bar{\ell} \ell$率的预测与将标准模型对单体和双体模式（$K$，$K^*$，$K\pi$）预测相加的结果良好一致。 这一观察使我们能够将包含性$b \to s \bar{\ell} \ell$率直接与数据进行比较。 这种比较显示数据中存在显著的不足（$\sim 2\sigma$），这与在低-$q^2$的独占模式中观察到的不足完全一致。 这提供了关于异常的$b \to s \bar{\ell} \ell$短距离相互作用的独立证据，不受强子形式因子不确定性的干扰。 为了测试该效应的短距离性质，我们使用第二种方法，其中我们在整个$q^2$区域分析独家的$B \to K^{(*)} \bar{\ell} \ell$数据。 在这里，使用了魅光子共振态的色散参数化后，我们为每个在$q^2$中的区间以及每种极化提取对通用威尔逊系数$C_9$的非标准模型贡献。 $q^2$的结果以及与极化无关性，以及与包含确定的一致性，提供了对该效应短距离性质的一致性检查。 显示英文摘要

摘要： The rare $B \to K^{(*)} \bar{\ell} \ell$ decays exhibit a long-standing tension with Standard Model (SM) predictions, which can be attributed to a lepton-universal short-distance $b \to s \bar{\ell} \ell$ interaction. We present two novel methods to disentangle this effect from long-distance dynamics: one based on the determination of the inclusive $b \to s \bar{\ell} \ell$ rate at high dilepton invariant mass ($q^2\geq 15~{\rm GeV}^2$), the other based on the analysis of the $q^2$ spectrum of the exclusive modes $B \to K^{(*)} \bar{\ell} \ell$ (in the entire $q^2$ range). Using the first method, we show that the SM prediction for the inclusive $b \to s \bar{\ell} \ell$ rate at high dilepton invariant mass is in good agreement with the result obtained summing the SM predictions for one- and two-body modes ($K$, $K^*$, $K\pi$). This observation allows us to perform a direct comparison of the inclusive $b \to s \bar{\ell} \ell$ rate with data. This comparison shows a significant deficit ($\sim 2\sigma$) in the data, fully compatible with the deficit observed at low-$q^2$ on the exclusive modes. This provides independent evidence of an anomalous $b \to s \bar{\ell} \ell$ short-distance interaction, free from uncertainties on the hadronic form factors. To test the short-distance nature of this effect we use a second method, where we analyze the exclusive $B \to K^{(*)} \bar{\ell} \ell$ data in the entire $q^2$ region. Here, after using a dispersive parametrization of the charmonia resonances, we extract the non-SM contribution to the universal Wilson coefficient $C_9$ for every bin in $q^2$ and for every polarization. The $q^2$- and polarization-independence of the result, and its compatibility with the inclusive determination, provide a consistency check of the short-distance nature of this effect.