论文标题
晶格动机的QCD耦合和对MUON $ G-2 $的HADRONIC贡献
Lattice-motivated QCD coupling and hadronic contribution to muon $g-2$
论文作者
论文摘要
我们提出了QCD耦合的更新版本，该版本满足了各种出于身体动机的条件：在高动量下，它实际上与扰动QCD（PQCD）耦合相吻合；在中级动力上，它正确再现了半峰tau衰变的物理学；在非常低的动量下，它被大量晶格计算所暗示的抑制作用。从此处进行了较早提出的分析，从某种意义上说，Adler函数在制度中$ | q^2 | \ Lessim 1 \ {\ rm Gev}^2 $，通过一种肾上腺动机的重新召集方法评估。然后，此处使用此ADLER功能在评估与Semihadronic（无固定）$τ$ -DECAY光谱函数相关的数量中，包括（V+a）-Channel中的Borel-Laplace Sum规则。然后将分析扩展到对哑光异常磁矩贡献的耐水化真空极化的评估，$a_μ^{\ rm具有（1）} $，在此中，我们在adler函数中包括了V-channel the Fight-Twist高折OPE，这些术语受到群众的调节（ir）受期望的$ $ 1 $ 1 $ 1 $ 1 $ 1 $ 1 $ 1 $ 1 $ 1 $ 1 $ 1 $ 1 $ g。如果冷凝物$ \ langle o_4 \ rangle _ {\ rm v+a} $，则可以使用上述IR调节的质量参数的$a_μ^{\ rm的正确值重现（1）} $。这种限制和对拟合质量的要求对各种提到的总和规则的要求，然后使我们限制了$ 0.1171 <α_s（m_z^2; {\ overline {ms}}}）<0.1180 $。
We present an updated version of a QCD coupling which fulfills various physically motivated conditions: at high momenta it practically coincides with the perturbative QCD (pQCD) coupling; at intermediate momenta it reproduces correctly the physics of the semihadronic tau decay; and at very low momenta it is suppressed as suggested by large-volume lattice calculations. An earlier presented analysis is updated here in the sense that the Adler function, in the regime $|Q^2| \lesssim 1 \ {\rm GeV}^2$, is evaluated by a renormalon-motivated resummation method. This Adler function is then used here in the evaluation of the quantities related with the semihadronic (strangeless) $τ$-decay spectral functions, including Borel-Laplace sum rules in the (V+A)-channel. The analysis is then extended to the evaluation of the hadronic vacuum polarization contribution to the muon anomalous magnetic moment, $a_μ^{\rm had(1)}$, where we include in the Adler function the V-channel higher-twist OPE terms which are regulated in the infrared (IR) by mass parameters which are expected to be $\lesssim 1$ GeV. The correct value of $a_μ^{\rm had(1)}$ can be reproduced with the mentioned IR-regulating mass parameters if the value of the condensate $\langle O_4 \rangle_{\rm V+A}$ is positive (and thus the gluon condensate value is positive). This restriction and the requirement of the acceptable quality of the fits to the various mentioned sum rules then lead us to the restriction $0.1171 < α_s(M_Z^2;{\overline{MS}}) < 0.1180$.
