论文标题
用高斯内核涂抹的R-Ratio的晶格计算
Lattice calculation of the R-ratio smeared with Gaussian kernel
论文作者
论文摘要
$ e^+e^ - \ to $ hadrons和$ e^+e^ - \与μ^+μ^ - $的横截面的比率$ r（e）$是标准模型Hadroonic扇形的有价值的能量依赖探针。此外，$ r（e）$的实验测量值是对MUON $ G-2 $的领先的HADRONIC真空极化贡献的分散计算的输入，这些贡献与直接的晶格计算以及Muon $ G-2 $实验具有显着张力。在本次演讲中，我们讨论了我们对$ r（e）$的第一原理格子研究的结果。通过使用最近提出的方法来从欧几里得晶格相关器中提取涂片的光谱密度，我们计算了$ r（e）$与具有不同宽度的高斯内核$σ$ $σ$和中央能量高达$ 2.5 $ GEV的高斯核。我们的理论结果已与用相同的高斯内核涂片的实验结果的KNT19 [1]进行了比较，并且已经观察到张力（约三个标准偏差），以$σ\ sim 600 $ MEV和中央能量左右$ρ$ - $ρ$ resonance Peak。
The ratio $R(E)$ of the cross-sections for $e^+e^-\to$ hadrons and $e^+e^-\to μ^+μ^-$ is a valuable energy-dependent probe of the hadronic sector of the Standard Model. Moreover, the experimental measurements of $R(E)$ are the inputs of the dispersive calculations of the leading hadronic vacuum polarization contribution to the muon $g-2$ and these are in significant tension with direct lattice calculations and with the muon $g-2$ experiment. In this talk we discuss the results of our first-principles lattice study of $R(E)$. By using a recently proposed method for extracting smeared spectral densities from Euclidean lattice correlators, we have calculated $R(E)$ convoluted with Gaussian kernels of different widths $σ$ and central energies up to $2.5$ GeV. Our theoretical results have been compared with the KNT19 [1] compilation of experimental results smeared with the same Gaussian kernels and a tension (about three standard deviations) has been observed for $σ\sim 600$ MeV and central energies around the $ρ$-resonance peak.
