论文标题
使用晶状体QCD和Unitarity B衰变的LFU比率
LFU ratios in B decays using Lattice QCD and Unitarity
论文作者
论文摘要
我们介绍了将基于单位性的分散矩阵方法应用于半乳房充电$ b $衰减的结果。这种方法允许实现对望子形式因素的非扰动和完全独立于模型的确定。从晶格结果开始以大量转移的巨大值可用，在其整个运动学范围内的形式因素的行为是在不引入其动量依赖性的任何明确参数化的情况下获得的。我们将通过计算$ b \ \ d^{（*）} \ellν$和$ b \ w \π\ellν$衰减的分支分数的$τ/μ$ $比率来重点关注Lepton风味普遍性的分析。最重要的结果是，第一次，SM期望值与Lepton风味普遍性比率的测量值之间的差异是分别分别分别为两个通道的1.3 $σ$水平的D^{（*）} \ellν$衰减。
We present the results of the application of the unitarity-based Dispersion Matrix approach to semileptonic charged-current $B$ decays. This method allows to achieve a non-perturbative and completely model-independent determination of the hadronic form factors. Starting from lattice results available at large values of the momentum transfer, the behaviour of the form factors in their whole kinematical range is obtained without introducing any explicit parameterization of their momentum dependence. We will focus on the analysis of Lepton Flavour Universality by computing the $τ/μ$ ratios of the branching fractions of the $B \to D^{(*)} \ell ν$ and $B \to π\ell ν$ decays. The most important result is that, for the first time, the discrepancies between the SM expectation values and the measurements of the Lepton Flavour Universality ratios for the $B \to D^{(*)} \ell ν$ decays are reduced at the 1.3$σ$ level for each of the two channels, separately.
