Interplay between SM precision, BSM physics, and the measurements of αhad in μ‐e scattering
Interplay between SM precision, BSM physics, and the measurements of αhad in μ‐e scattering
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SM 精度、BSM 物理特性和 π 散射中的 α 测量之间的相互作用
DOI：
10.1103/physrevd.100.035030
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发表时间：
2019
影响因子：
5
通讯作者：
Williams, Ciaran
中科院分区：
文献类型：
--
作者：
Schubert, Ulrich;Williams, Ciaran
μ子电子散射实验，如建议的MUonE实验提供了一个机会，提高测量的领先阶强子运行，表示。这样的测量可以用来减少理论上的不确定性预测的μ子的异常磁矩。目前，这个观测值的理论和数据之间存在差异，这可能可以用超越标准模型（BSM）物理学来解释。在这里，我们研究了缺失的标准模型（SM）高阶修正和BSM物理对所提出的测量的可能影响。原则上，任何一个都可以间接地适应，如果在应用程序中使用，就会导致不一致。文献建议理论准确度的目标值为10 ppm。我们使用各种方法详细评估了该目标的有效性，发现1 ppm的目标是一个更保守的估计，以确保缺失的高阶不占主导地位的理论不确定性。对于潜在的BSM贡献，我们研究了各种模型，首先在树和循环级别。特别令人感兴趣的是来自暗光子模型的影响，这可能会影响所需精度的测量。在环路级，一般存在一个运动抑制足以减少BSM的贡献，可以忽略提取的水平。
Muon electron scattering experiments such as the proposed MUonE experiment offer an opportunity for an improved measurement of the leading-order hadronic running of, denoted. Such a measurement could be utilized to reduce the theoretical uncertainty on the prediction of the anomalous magnetic moment of the muon,. Currently, there is a discrepancy between theory and data for this observable, which could potentially be explained by beyond the Standard Model (BSM) physics. Here we investigate the possible impact of missing Standard Model (SM) higher-order corrections and BSM physics on the proposed measurement of. In principle, either could be indirectly fitted into, causing inconsistencies if used in aapplication. The literature suggests a target of 10 ppm on the cross section for the theoretical accuracy. We assess the validity of this target in detail using a variety of methods, finding that a 1 ppm target is a more conservative estimate to ensure that missing higher orders do not dominate the theoretical uncertainty. For the potential BSM contributions, we study various models which contribute first at tree and loop level. Of particular interest is the impact from dark photon models, which can potentially affect the measurement ofat the desired accuracy. At loop level, there exists in general a kinematic suppression adequate to reduce the BSM contributions to a level which can be neglected for the extraction of.