论文标题
Unimarity和lattice QCD的独家B-Meson半衰减衰减
Exclusive B-meson semileptonic decays from unitarity and lattice QCD
论文作者
论文摘要
我们检查了半蛋白质的$ b \ to d^{（*）} \ellν_\ ell $和$ b \ toπ\ elnν_\ ell $衰变，采用基于单位性的分散矩阵（DM）方法，该方法允许在其整个范围内的相关形式（FFS）的形状（ffs）的形状（ffs）的形状（ffs）的形状，仅使用其整个范围），该范围是QC。 4-摩梅特转移，而没有对其动量依赖性做出任何假设。此外，实验数据不用于约束FFS的形状，而只是为了获得我们最终独家确定$ \ vert v_ {cb} \ vert $和$ \ vert v_ {ub} {ub} \ vert $，namely：$ \ vert v_ {cb} {cb} {cb} \ vert \ vert \ cdot \ cdot $ cdot 10^3 = 3 = 3 = 3 = 3 = 3 = 3 = 3 = 3 = 3 = 3 = 3 = 3 = 3 = 3 = 3 = 3 = 3 = 3 = 41. v_ {ub} \ vert \ cdot 10^3 = 3.88 \ pm 0.32 $，这与最新的包含性确定在$1σ$级别或更高的情况下是一致的。我们对FFS的计算允许获得差异衰减率的$τ/μ$比率的纯理论估计，$ r（d）= 0.296 \ pm 0.008 $和$ r（d^*）= 0.275 \ pm 0.008 $，这与实验世界中的$ \ sime sime $ $ \ simeq 1.4 $ $ \ sime $ $ \ sime $ $ \ sime $ $ \ sime $ $ \ sime $ $ \ simeq 1.4 $ $ \ sime $ $ \ simeq 1.4 $ $ \ simeq 1.4 $ $ \ sime $ $。
We examine the semileptonic $B \to D^{(*)} \ell ν_\ell$ and $B \to π\ell ν_\ell$ decays adopting the unitarity-based Dispersive Matrix (DM) method, which allows to determine the shape of the relevant hadronic form factors (FFs) in their whole kinematical range, using only lattice QCD results available at large values of the 4-momentum transfer without making any assumption on their momentum dependence. Moreover, the experimental data are not used to constrain the shape of the FFs, but only to obtain our final exclusive determination of $\vert V_{cb} \vert$ and $\vert V_{ub} \vert$, namely: $\vert V_{cb} \vert \cdot 10^3 = 41.1 \pm 1.0$ and $\vert V_{ub} \vert \cdot 10^3 = 3.88 \pm 0.32$, which are consistent with the latest inclusive determinations at the $1 σ$ level or better. Our calculation of the FFs allows to obtain pure theoretical estimates of the $τ/ μ$ ratios of differential decay rates, $R(D) = 0.296 \pm 0.008$ and $R(D^*) = 0.275 \pm 0.008$, which turn out to be compatible with the experimental world averages within $\simeq 1.4$ standard deviations.
