论文标题
$ | v_ {cb} | $，Lepton风味普遍性和$ su（3）_f $对称性破坏$ b_s \ to d_s^{（*）} \ ell via
$|V_{cb}|$, Lepton Flavour Universality and $SU(3)_F$ symmetry breaking in $B_s \to D_s^{(*)} \ell ν_\ell$ decays through unitarity and lattice QCD
论文作者
论文摘要
除了众所周知的$ b \ to d^{（*）} \ ellν_\ ell $衰减，半蛋白质$ b_s \ to d_s^{（*）} \ ell v e ellν_\ ell $ processEs提供了确定cabobbo-kobayashi-maskawa（ckm）的可能性，可提供确定的可能性。我们实施了分散矩阵（DM）方法，以描述$ b_s \ to d_s^{（*）} $转换的hadro-form formation（ffs），从最近的4个摩尔元转移的大值开始。我们从实验数据中提取$ \ vert v_ {cb} \ vert $，从$ b_s \中获得$ \ vert v_ {cb} \ cdot \ cdot 10^3 =（41.7 \ pm 1.9）$从$ b_s \到d_s \ d_s \ ell g e el g e elnν_\ ell $ and $ \ ell $ and $ \ ell $ and $ \ ell $ and c. \ pm 2.4）$从$ b_s \到d_s^* \ellν_\ ell $衰减。在以$ \ vert v_ {cb} \ vert $为单位的值之后\ vert _ {\ rm {incl}} \ cdot 10^3 = 42.16 \ pm 0.50 $ [3] $1σ$级别。此外，我们通过计算总衰减率的$τ/ \ ell $比率（其中$ \ ell $是轻质Lepton）来测试Lepton风味普遍性（LFU），从而获得$ r（d_s）= 0.298 \，（5）$和$ r（5）$和$ r（d_s^*）= 0.250 \，（6）$。我们还通过比较输入半抑制的$ b \与d^{（*）} $和$ b_s \与d_s^{（*）} $ Channels的hadroonic ffs进行比较，解决了$ su（3）_f $对称破坏的问题。
In addition to the well-known $B \to D^{(*)} \ell ν_\ell$ decays, semileptonic $B_s \to D_s^{(*)} \ell ν_\ell$ processes offer the possibility to determine the Cabibbo-Kobayashi-Maskawa (CKM) matrix element $\vert V_{cb}\vert$. We implement the Dispersive Matrix (DM) approach to describe the hadronic Form Factors (FFs) for the $B_s \to D_s^{(*)}$ transition in the whole kinematical range, starting from recent Lattice QCD computations at large values of the 4-momentum transfer. We extract $\vert V_{cb} \vert$ from the experimental data, obtaining $\vert V_{cb} \vert \cdot 10^3 = (41.7 \pm 1.9)$ from $B_s \to D_s \ell ν_\ell$ and $\vert V_{cb} \vert \cdot 10^3 =(40.7 \pm 2.4)$ from $B_s \to D_s^* \ell ν_\ell$ decays. After averaging with the values of $\vert V_{cb} \vert$ obtained from the $B \to D^{(*)}$ channels [1,2] we get $\vert V_{cb} \vert \cdot 10^3 =(41.2 \pm 0.8)$, which is compatible with the most recent inclusive estimate $\vert V_{cb} \vert_{\rm{incl}} \cdot 10^3 = 42.16 \pm 0.50$ [3] at the $1 σ$ level. In addition we test the Lepton Flavour Universality (LFU) by computing the $τ/ \ell$ ratios of the total decay rates (where $\ell$ is a light lepton), obtaining $R(D_s) = 0.298\,(5)$ and $R(D_s^*)= 0.250\,(6)$. We also address the issue of the $SU(3)_F$ symmetry breaking by comparing the hadronic FFs entering the semileptonic $B \to D^{(*)}$ and $B_s \to D_s^{(*)}$ channels.
