论文标题
独家半乳房$ b \ toπ\ ellν_\ ell $和$ b_s \ to k \ ell v to k \ ellν_\ ell $ nitarity and lattice qcd衰减
Exclusive semileptonic $B \to π\ell ν_\ell$ and $B_s \to K \ell ν_\ell$ decays through unitarity and lattice QCD
论文作者
论文摘要
Cabibbo-Kobayashi-Maskawa（CKM）矩阵元素$ \ vert v_ {ub} \ vert $是从独家半蛋白质$ b \ toπ\ ell v \elν_\ ell $和$ b_s \ to k \ ell g e el g e el n Nimater-nimation depersrix the Inition distrix the Interrions depersrions的确定，从独家的半蛋白质$ b \到π\ ellν_\ ell $和$ b_s \ （FFS）在整个运动范围内。我们使用相关敏感性和ffs中的晶格计算，以$ $ q^2 $制度中的晶格计算，以便在低$ q^2 $区域中得出其行为，而无需假设任何特定的动量依赖性，并且不使用实验数据来限制其形状。然后，我们从实验数据中提取$ \ vert v_ {ub} \ vert $的提取，从$ \ vert v_ {ub} \ vert =（3.62 \ pm 0.47）\ cdot 10^{ - 3} $从$ b \ toπ$和$ \ vert v_ pm and $ \ vert v_ {3.48） \ cdot 10^{ - 3} $从$ b_s \到k $，平均产量$ \ vert v_ {ub} {ub} \ vert =（3.69 \ pm 0.34）\ cdot 10^{ - 3} $。这些结果与最新的包含值$ \ vert v_ {ub} \ vert_ {incl} = 4.13 \，（26）\ cdot 10^{ - 3} $在1 $σ$级别上。我们还提出了$τ/μ$衰减比率的纯粹理论估计，$ r^{τ/μ} _ {π（k）} $，归一化的前向不良$ \ bar {\ mathcal {\ Mathcal {\ Mathcal {a}}}}}} $ \ bar {\ Mathcal {a}} _ {polar}^{\ ell，π（k）} $。
The Cabibbo-Kobayashi-Maskawa (CKM) matrix element $\vert V_{ub}\vert$ is obtained from exclusive semileptonic $B \to π\ell ν_\ell$ and $B_s \to K \ell ν_\ell$ decays adopting the unitarity-based dispersion matrix approach for the determination of the hadronic form factors (FFs) in the whole kinematical range. We use lattice computations of the relevant susceptibilities and of the FFs in the large-$q^2$ regime in order to derive their behavior in the low-$q^2$ region without assuming any specific momentum dependence and without constraining their shape using experimental data. Then, we address the extraction of $\vert V_{ub}\vert$ from the experimental data, obtaining $\vert V_{ub}\vert = (3.62 \pm 0.47) \cdot 10^{-3}$ from $B \to π$ and $\vert V_{ub}\vert = (3.77 \pm 0.48) \cdot 10^{-3}$ from $B_s \to K$, which after averaging yield $\vert V_{ub}\vert = (3.69 \pm 0.34) \cdot 10^{-3}$. These results are compatible with the most recent inclusive value $\vert V_{ub} \vert_{incl} = 4.13\,(26) \cdot 10^{-3}$ at the 1$σ$ level. We also present purely theoretical estimates of the ratio of the $τ/μ$ decay rates $R^{τ/μ}_{π(K)}$, the normalized forward-backward asymmetry $\bar{\mathcal{A}}_{FB}^{\ell,π(K)}$ and the normalized lepton polarization asymmetry $\bar{\mathcal{A}}_{polar}^{\ell,π(K)}$.
