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arXiv 2008.08107hep-phhep-ex
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$a_μ$和$α_{QED}$之间的相关性对EW拟合的影响

Impact of correlations between $a_μ$ and $α_{QED}$ on the EW fit

Bogdan Malaescu, Matthias Schott

摘要:

我们研究了潜在的影响,对电弱(EW)适合由于当前确定的强子真空极化(HVP)的贡献μ子的异常磁矩($a_μ$)之间的紧张局势,基于现象学色散积分使用测量的强子谱或格点量子色动力学计算。本文还研究了电流张力对$a_μ$实验测量值和基于HVP唯象计算的总理论预测值之间的影响。研究中考虑了$a_μ$理论预测和$α_{QED}$运行的不确定性之间的相关性。我们的结论是,在不太可能的情况下,对EW拟合的影响可能很大,涉及全球的全部HVP贡献的变化,而它是小得多,如果移动被限制在一个较低的质量范围和/或如果在$α_{QED}$的移动是通过适当使用的相关性从$a_μ$。实际上,后一种情况仅意味着EW拟合的$χ^2/n.d.f.$最多增加2.6/16,并且所得拟合参数值的变化相对较小。

英文摘要:

We study the potential impact on the electroweak (EW) fits due to the tensions between the current determinations of the hadronic vacuum polarisation (HVP) contributions to the anomalous magnetic moment of the muon ($a_μ$), based on either phenomenological dispersion integrals using measured hadronic spectra or on Lattice QCD calculations. The impact of the current tension between the experimental measurement of $a_μ$ and the total theoretical prediction based on the phenomenological calculations of the HVP are also studied. The correlations between the uncertainties of the theoretical predictions of $a_μ$ and of the running of $α_{QED}$ are taken into account in the studies. We conclude that the impact on the EW fit can be large in improbable scenarios involving global shifts of the full HVP contribution, while it is much smaller if the shift is restricted to a lower mass range and/or if the shift in $α_{QED}$ is obtained from that in $a_μ$ through appropriate use of the correlations. Indeed, the latter scenarios only imply at most a 2.6/16 increase in the $χ^2/n.d.f.$ of the EW fits and relatively small changes for the resulting fit parameter values.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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