Muon g - 2 and ? a connection
Muon g - 2 and ? a connection
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介子 g-2 和 ?
DOI：
10.1103/physrevd.102.033002
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发表时间：
2020
影响因子：
5
通讯作者：
Keshavarzi A
中科院分区：
文献类型：
--
作者：
Keshavarzi A
标准模型理论与 μ 子磁矩异常实验测量之间的差异，通过它们对强子真空极化效应的共同依赖性与精确电弱 (EW) 预测相关。总截面的相同数据被用作色散关系的输入，以估计强子真空极化贡献，以及对极点运行 QED 耦合的五种强子贡献，这进入自然关系和全局 EW 拟合。 EW 拟合预测与从色散关系方法获得的结果非常吻合，但表现出较小的中心值，表明比当前预期的差异更大。假设这种差异可能是由于不可预见的缺失贡献造成的，对全球电子战拟合的影响和从全球电子战拟合中获得的影响进行了调查。发现桥接所需的移位在 95% C.L. 的范围内被排除在外。此外，考虑到强子截面所需的增加，产生低于该能量的前景被认为是不可能的。强子数据的这种假设变化也被发现会影响其他相关的可观测值，例如电子异常、重新缩放的比率Re/μ=(mμ/me)2(aehad,LO VP/aμhad,LO VP)以及低能量下弱混合角的运行，尽管这些后果目前约束性较小。
The discrepancy between the Standard Model theory and experimental measurement of the muon magnetic moment anomaly,, is connected to precision electroweak (EW) predictions via their common dependence on hadronic vacuum polarization effects. The same data for the totalcross section,, are used as input into dispersion relations to estimate the hadronic vacuum polarization contributions,, as well as the five-flavor hadronic contribution to the running QED coupling at the-pole,, which enters natural relations and global EW fits. The EW fit prediction ofagrees well withobtained from the dispersion relation approach, but exhibits a smaller central value suggestive of a larger discrepancythan currently expected. Postulating that thedifference may be due to unforeseen missingcontributions, implications for,andobtained from global EW fits are investigated. Shifts inneeded to bridgeare found to be excluded aboveat the 95% C.L. Moreover, prospects fororiginating below that energy are deemed improbable given the required increases in the hadronic cross section. Such hypothetical changes to the hadronic data are also found to affect other related observables, such as the electron anomaly,, the rescaled ratio Re/μ=(mμ/me)2(aehad,LO VP/aμhad,LO VP), and the running of the weak mixing angle at low energies, although the consequences of these are currently less constraining.