论文标题
稀有$ k $和$ b $衰减的标准模型预测没有$ | v_ {cb} | $和$ | v_ {ub} | $不确定性
Standard Model Predictions for Rare $K$ and $B$ Decays without $|V_{cb}|$ and $|V_{ub}|$ Uncertainties
论文作者
论文摘要
$ | v_ {cb} | $和$ | v_ {ub} | $之间的包容性和独家确定之间的持久紧张关系削弱了理论上清洁稀有$ k $和$ b $衰减的能力，以搜索新物理（NP）。我们通过考虑在各种分支比率的SM适当比率内实际上可以消除这种不确定性。这包括$ k^+\toπ^+bbarν$，$ k_ {l} \toπ^0ν\barν$，$ k_s \toμ^+μ^ - $，$ b_ { $ε_k$，$Δm_d$，$Δm_s$和混合诱导的CP-Asmymmetry $ s_ {ψk_s} $，所有这些都已经非常精确地测量，在此分析中起着重要作用。 The highlights of our analysis are 16 $|V_{cb}|$ and $|V_{ub}|$ independent ratios that often are independent of the CKM arameters or depend only on the angles $β$ and $γ$ in the Unitarity Triangle with $β$ already precisely known and $γ$ to be measured precisely in the coming years by the LHCb and Belle II collaborations.一旦$γ$一旦测量$γ$，就可以准确地测量了这16个比率，预计将成为寻找新物理学的强大工具。假设$ |ε_k| $和$ s_ {ψk_s} $在$ | $ \ MATHCAL {b}（k_l \toπ^0ν\barν）_ \ text {sm} =（2.94 \ pm 0.15）\ times 10^{ - 11} $。这是迄今为止最精确的确定。假设在$Δm_{s，d} $中没有NP允许在我们的论文中考虑的所有$ b $衰减分支比率获得类似的结果，而没有任何CKM不确定性。
The persistent tensions between inclusive and exclusive determinations of $|V_{cb}|$ and $|V_{ub}|$ weaken the power of theoretically clean rare $K$ and $B$ decays in the search for new physics (NP). We demonstrate how this uncertainty can be practically removed by considering within the SM suitable ratios of various branching ratios. This includes the branching ratios for $K^+\toπ^+ν\barν$, $K_{L}\toπ^0ν\barν$, $K_S\toμ^+μ^-$, $B_{s,d}\toμ^+μ^-$ and $B\to K(K^*)ν\barν$. Also $ε_K$, $ΔM_d$, $ΔM_s$ and the mixing induced CP-asymmetry $S_{ψK_S}$, all measured already very precisely, play an important role in this analysis. The highlights of our analysis are 16 $|V_{cb}|$ and $|V_{ub}|$ independent ratios that often are independent of the CKM arameters or depend only on the angles $β$ and $γ$ in the Unitarity Triangle with $β$ already precisely known and $γ$ to be measured precisely in the coming years by the LHCb and Belle II collaborations. Once $γ$ Once $γ$ is measured precisely these 16 ratios taken together are expected to be a powerful tool in the search for new physics. Assuming no NP in $|ε_K|$ and $S_{ψK_S}$ we determine independently of $|V_{cb}|$: $\mathcal{B}(K^+\toπ^+ν\barν)_\text{SM}= (8.60\pm0.42)\times 10^{-11}$ and $\mathcal{B}(K_L\toπ^0ν\barν)_\text{SM}=(2.94\pm 0.15)\times 10^{-11}$. This are the most precise determinations to date. Assuming no NP in $ΔM_{s,d}$ allows to obtain analogous results for all $B$ decay branching ratios considered in our paper without any CKM uncertainties.
