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arXiv 2103.13149hep-ph
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$B-L$扩展的双Higgs模型中的反跷跷板和$(g-2)$反常

Inverse seesaw and $(g-2)$ anomalies in $B-L$ extended two Higgs doublet model

Tanmoy Mondal, Hiroshi Okada

摘要:

本文提出了一个规范的$U(1)_{B-L}$扩展的双Higgs二重态模型来解释中微子质量和轻子反常磁矩($g-2$)。中微子质量是通过引入单重态费米子的反跷跷板机制产生的。特别地,我们根据费米实验室E989实验的最新报告更新了μ子$g-2$的结果,表明了$a_μ^{\rm FNAL}=116592040(54)\times 10^{-11}$。结合BNL结果,我们在4.2 $σ$处与标准模型预测值$Δa_μ=(2.51\pm 5.9)\times10^{-10}$存在以下偏差。由于对$U(1)_{B-L}\times Z_2$对称性进行了适当的分配,并使$(20\lesssim)\tanβ$更大,从而使中性费米子之间实现了自然的层次结构。通过引入一个单重态单电荷玻色子,可以在单圈能级上诱导出轻子反常磁矩。这种带电标量在避免这些现象的手性抑制中起着重要作用。我们证明了在满足所有的味约束,如$μ\to eγ$和味守恒的轻子$Z$玻色子衰变后,可以得到相当大的轻子($g-2$)。

英文摘要:

We propose a gauged $U(1)_{B-L}$ extended two Higgs doublet model to explain both neutrino mass and lepton anomalous magnetic moments ($g-2$). Neutrino mass is generated via an inverse seesaw mechanism by introducing singlet fermions. Especially, we update the result of muon $g-2$ in light of the very recent report by E989 experiment at Fermilab, indicating $a_μ^{\rm FNAL}=116592040(54)\times 10^{-11}$. Combining BNL result, we have the following deviation from the standard model prediction $Δa_μ=(2.51\pm 5.9)\times10^{-10}$ at 4.2 $σ$. Thanks to an appropriate assignment for $U(1)_{B-L}\times Z_2$ symmetry and larger $(20\lesssim)\tanβ$ that is favoured by type-X model, we realize natural hierarchies among neutral fermions. The lepton anomalous magnetic moments can be induced at the one loop level by introducing an iso-spin singlet singly-charged boson. This charged scalar plays a significant role in evading chiral suppression of these phenomenologies. We show sizable lepton ($g-2$) can be obtained after satisfying all the flavour constraints, such as $μ\to eγ$ and flavour conserving leptonic $Z$ boson decays.

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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