论文标题
半衰减的衰减中的强子和Lepton张量，包括新物理
Hadron and lepton tensors in semileptonic decays including new physics
论文作者
论文摘要
我们扩展了半衰减衰减的一般框架，最初是在N. n. n. n. n. [物理。 Rev. D100，113007（2019）]，加上新物理（NP）张量术语。通过这种方式，现已包括在Lepton风味普遍性（LFUV）研究中考虑的所有NP有效的汉密尔顿人（LFUV）研究。此外，我们现在还提供一般的表达式，允许复杂的威尔逊系数。开发的计划是完全笼统的，可以应用于任何充电的当前半衰减衰减，涉及任何夸克口味或初始和最终的强子状态。我们表明，所有的HADRONIC输入（包括NP效应）都可以通过16个Lorentz标量结构函数进行参数化。在这项工作的第二部分中，我们使用这种形式主义来获得$λ_b\ toλ_cτ\barν_τ$半衰减衰减中的完整NP效应，如果最终确认了LFUV，也可以看到LFUV。我们强调质量中心（cm）$ d^2γ/（dΩd\cosθ_\ ell）$和实验室（实验室）$ d^2γ/（dΩDe_\ ell）$差异衰减宽度的相关性。尽管在NP项中具有非常不同优势的模型给出了相同的差异$dγ/dΩ$和此衰减的总衰减宽度，但他们预测了一些确定上述两个分布的$ \cosθ_\ ell $和$ e_ \ ell $系数的$ \cosθ_\ ell $和$ e_ \ ell $系数功能的非常不同的数值结果。因此，CM $ d^2γ/（dΩd\cosθ_\ ell）$和LAB $ d^2γ/（dΩde_\ ell）$差衰变宽度的组合分析将有助于澄清哪种NP是更好的候选者，以解释LFFUV。
We extend our general framework for semileptonic decay, originally introduced in N. Penalva et al. [Phys. Rev. D100, 113007 (2019)], with the addition of new physics (NP) tensor terms. In this way, all the NP effective Hamiltonians that are considered in lepton flavour universality violation (LFUV) studies have now been included. Besides, we now also give general expressions that allow for complex Wilson coefficients. The scheme developed is totally general and it can be applied to any charged current semileptonic decay, involving any quark flavors or initial and final hadron states. We show that all the hadronic input, including NP effects, can be parametrized in terms of 16 Lorentz scalar structure functions. In the second part of this work, we use this formalism to obtain the complete NP effects in the $Λ_b\to Λ_c τ\barν_τ$ semileptonic decay, where LFUV, if finally confirmed, is also expected to be seen. We stress the relevance of the center of mass (CM) $d^2Γ/(dωd\cosθ_\ell)$ and laboratory (LAB) $d^2Γ/(dωdE_\ell)$ differential decay widths. While models with very different strengths in the NP terms give the same differential $dΓ/dω$ and total decay widths for this decay, they predict very different numerical results for some of the $\cosθ_\ell$ and $E_\ell$ coefficient-functions that determine the above two distributions. Thus, the combined analysis of the CM $d^2Γ/(dωd\cosθ_\ell)$ and LAB $d^2Γ/ (dωdE_\ell)$ differential decay widths will help clarifying what kind of NP is a better candidate in order to explain LFUV.
