论文标题
探测晶格上的能量隔离RATIO
Probing the energy-smeared R-ratio on the lattice
论文作者
论文摘要
我们提出了对$ e^+e^ - $ e^+e^ - $ $ $ rattio的第一原理晶格QCD调查，$ e^+e^ - $ $ cross to Hadrons in Muons中。通过使用参考文献[1]的方法，该方法允许从欧几里得相关器提取涂抹光谱密度，我们计算了$ r $ ratatio，用高斯涂片核心响起的$ 600 $ MEV和中央能量的高斯涂片核从220美元的$ 220 MEV $ 2.5 $ 2.5 $ GEV。将我们的理论结果与通过相同核的KNT19汇编[2]获得的KNT19汇编[2]获得的相应数量进行了比较，并通过将高斯在该地区的高斯人围绕$ρ$差异峰的居中，观察到了大约三个标准偏差的紧张。从现象学的角度来看，我们尚未在计算QED和强烈的均质校正中包括，这可能会影响观察到的张力。从方法论的角度来看，我们的计算表明，可以在晶格上以精确度的水平研究高斯能量箱中的$ r $ ratatio，以便对标准模型进行精确测试。
We present a first-principles lattice QCD investigation of the $R$-ratio between the $e^+e^-$ cross-section into hadrons and that into muons. By using the method of Ref.[1], that allows to extract smeared spectral densities from Euclidean correlators, we compute the $R$-ratio convoluted with Gaussian smearing kernels of widths of about $600$ MeV and central energies from $220$ MeV up to $2.5$ GeV. Our theoretical results are compared with the corresponding quantities obtained by smearing the KNT19 compilation [2] of $R$-ratio experimental measurements with the same kernels and, by centring the Gaussians in the region around the $ρ$-resonance peak, a tension of about three standard deviations is observed. From the phenomenological perspective, we have not included yet in our calculation QED and strong isospin-breaking corrections and this might affect the observed tension. From the methodological perspective, our calculation demonstrates that it is possible to study the $R$-ratio in Gaussian energy bins on the lattice at the level of accuracy required in order to perform precision tests of the Standard Model.
