论文标题
$η'\toπ^+π^-γ$和$η'\ to \ ell^+\ ell^-γ$的色散分析
A dispersive analysis of $η'\toπ^+π^-γ$ and $η'\to \ell^+\ell^-γ$
论文作者
论文摘要
我们提出了$η''$过渡形式的分散表示形式，它允许人们以一致的方式对Isoscalar和ISOVECTOR贡献中的$ρ$ - $ω$混合的影响进行计算。使用这种形式主义，我们分析了有关$η'\至π^+π^-γ$的最新数据，以分别限制外形的等级部分，并与Pion Vector form sours的数据组合。作为第一个应用程序，我们将结果与外形层的等效部分的最新输入结合在一起，以预测$η'\ to \ ell^+el^+el^el^ell^-γ$的相应频谱，尤其是我们找到坡度参数$ b_ {η} = 1.431（23）\，\，\，\，\ fext {随着后一个过程的即将到来的数据，我们的结果建立了必要的框架，以改善$η''$ - 极点对MUON的异常磁矩的贡献，该框架使用$η'$衰减通道的实验输入。
We present a dispersive representation of the $η'$ transition form factor that allows one to account, in a consistent way, for the effects of $ρ$-$ω$ mixing in both the isoscalar and the isovector contributions. Using this formalism, we analyze recent data on $η'\to π^+π^-γ$ to constrain the isovector part of the form factor, individually and in combination with data for the pion vector form factor. As a first application, we use our results, in combination with the most recent input for the isoscalar part of the form factor, to predict the corresponding spectrum of $η'\to\ell^+\ell^-γ$, in particular we find the slope parameter $b_{η'}=1.431(23)\, \text{GeV}^{-2}$. With forthcoming data on the latter process, our results establish the necessary framework to improve the evaluation of the $η'$-pole contribution to the anomalous magnetic moment of the muon using experimental input from both $η'$ decay channels.
