标题： 第一例基于格点QCD的charmed-strange重子的半轻子衰变确定$Ξ_c$ 显示英文标题

标题： First Lattice QCD determination of semileptonic decays of charmed-strange baryons $Ξ_c$

摘要： 尽管标准模型是描述粒子物理学中所有相互作用和组分的最成功理论，但它已经接受了四十多年的不断检验。 粲夸克的弱衰变可以测量不同家族夸克之间的耦合强度，并且是探测CP破坏的理想探针。 作为含有三个不同味的最低重奇异重子，$\Xi_c$重子（由$csu$或$csd$组成）已经在大型强子对撞机上的实验以及电子-正电子碰撞中得到了广泛研究。 然而，理论知识的缺乏成为不可避免的障碍。 在这项工作中，我们使用最先进的格点QCD技术，并生成了两种晶格间距下的2+1 clover费米子系综，分别为$a=(0.108{\rm fm},0.080{\rm fm})$。 然后，我们给出了首个由{\it 从头计算}格点QCD确定的控制$\Xi_{c}\to \Xi \ell^+\nu_{\ell}$的形式因子，类似于著名的核子$\beta$衰变。 我们的理论结果对于衰变宽度与ALICE和Belle合作组的最新测量结果一致，并且精度提高了约两倍。 结合实验测量，我们独立确定了夸克混合矩阵元 $|V_{cs}|$，其结果与其他确定结果一致。 显示英文摘要

摘要： While the standard model is the most successfully theory to describe all interactions and constituents in elementary particle physics, it has been constantly examined for over four decades. Weak decays of charm quarks can measure the coupling strength of quarks in different families and serve as an ideal probe for CP violation. As the lowest charm-strange baryons with three different flavors, $\Xi_c$ baryons (made of $csu$ or $csd$) have been extensively studied in experiments at the large hadron collider and in electron-positron collision. However the lack of reliable knowledge in theory becomes the unavoidable obstacle in the way. In this work, we use the state-of-the-art Lattice QCD techniques, and generate 2+1 clover fermion ensembles with two lattice spacings, $a=(0.108{\rm fm},0.080{\rm fm})$. We then present the first {\it ab-initio} lattice QCD determination of form factors governing $\Xi_{c}\to \Xi \ell^+\nu_{\ell}$, analogous with the notable $\beta$-decay of nuclei. Our theoretical results for decay widths are consistent with and about two times more precise than the latest measurements by ALICE and Belle collaborations. Together with experimental measurements, we independently determine the quark-mixing matrix element $|V_{cs}|$, which is found in good agreement with other determinations.