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arXiv 1902.05075hep-phastro-ph.COhep-ex
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再论μ子反常磁矩的暗光子解释

Revisiting the Dark Photon Explanation of the Muon Anomalous Magnetic Moment

Gopolang Mohlabeng

备注：
5 pages + references, 3 figures
发表信息：
Phys. Rev. D 99, 115001 (2019)
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摘要：

一种被称为“暗光子”或$A^{\prime}$的大质量$U(1)^{\prime}$规范玻色子，长期以来一直被认为是对μ子异常磁矩（$g_μ - 2$）的实验测量和理论测定之间存在差异的潜在解释。最近，实验结果已经排除了这种可能性，因为暗光子只表现出可见或不可见的衰变。在这项工作中，我们重新审视这一想法，并考虑一个模型，其中$A^{\prime}$耦合非弹性的暗物质和一个兴奋的暗扇区状态，导致一个更奇特的衰变拓扑结构，我们称之为半可见衰变。我们发现，对于暗扇区状态之间的大质量分裂，这种衰变模式被增强，削弱了以前不可见的衰变暗光子的界限。因此，$A^{\prime}$解决了参数空间区域中的$g_μ - 2$异常，宇宙中的热暗物质成分很容易解释。有趣的是，我们讨论的半可见事件可能已经被寻找不可见暗光子衰变的实验否决了。对数据的重新分析和未来的搜索可能是至关重要的，在揭示这种奇异的衰变模式或关闭窗口的暗光子解释的$g_μ - 2$异常。

英文摘要：

A massive $U(1)^{\prime}$ gauge boson known as a "dark photon" or $A^{\prime}$, has long been proposed as a potential explanation for the discrepancy observed between the experimental measurement and theoretical determination of the anomalous magnetic moment of the muon, ($g_μ - 2$) anomaly. Recently, experimental results have excluded this possibility for a dark photon exhibiting exclusively visible or invisible decays. In this work, we revisit this idea and consider a model where $A^{\prime}$ couples inelastically to dark matter and an excited dark sector state, leading to a more exotic decay topology we refer to as a semi-visible decay. We show that for large mass splittings between the dark sector states this decay mode is enhanced, weakening the previous invisibly decaying dark photon bounds. As a consequence, $A^{\prime}$ resolves the $g_μ - 2$ anomaly in a region of parameter space the thermal dark matter component of the Universe is readily explained. Interestingly, it is possible that the semi-visible events we discuss may have been vetoed by experiments searching for invisible dark photon decays. A re-analysis of the data and future searches may be crucial in uncovering this exotic decay mode or closing the window on the dark photon explanation of the $g_μ - 2$ anomaly.

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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