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arXiv 2403.02897hep-phhep-ex
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稀有$B$和$K$衰变在一个scotogenic模型中

Rare $B$ and $K$ decays in a scotogenic model

Chuan-Hung Chen, Cheng-Wei Chiang

AI总结:

该研究扩展scotogenic模型,引入暗粒子以辐射产生中微子质量,解决缪子g-2和B_s→μμ张力,并将B^+→K^+νν̄分支比增强至SM的2倍,同时研究K→πνν̄衰变。

摘要:

一个scotogenic模型可以辐射性地产生观测到的中微子质量,提供暗物质候选者,并导致罕见的轻子味破坏过程。我们旨在扩展该模型,以在scotogenesis框架内建立与夸克味相关过程的潜在联系,增强Belle II合作组观测到的$B^+\ o K^+ ν\arν$异常大的分支比(BR)。同时,该模型可以解决味物理中一些实验测量与标准模型(SM)预言之间的张力,如缪子$g-2$过剩和$B_s \ o μ^- μ^+$的较高BR。我们在模型中引入以下暗粒子:一个中性单态狄拉克型轻子($N$);两个惰性希格斯双重态($η_{1,2}$),其中一个携带轻子数;一个带电单态暗标量($χ^+$),以及一个单态矢量型上型暗夸克($T$)。前两个实体负责辐射性中微子质量,而$χ^+$耦合到右手夸克和轻子,可以解决缪子$g-2$和$B_s\ o μ^- μ^+$中存在的张力。此外,通过暗$T$和带电标量的中介,$B^+ \ o K^+ ν\arν$的BR相对于SM预言可以增强至多2倍。另外,我们还研究了其对$K\ o πν\arν$衰变的影响。

英文摘要:

A scotogenic model can radiatively generate the observed neutrino mass, provide a dark matter candidate, and lead to rare lepton flavor-violating processes. We aim to extend the model to establish a potential connection to the quark flavor-related processes within the framework of scotogenesis, enhancing the unexpectedly large branching ratio (BR) of $B^+\to K^+ ν\barν$, observed by Belle II Collaboration. Meanwhile, the model can address tensions between some experimental measurements and standard model (SM) predictions in flavor physics, such as the muon $g-2$ excess and the higher BR of $B_s \to μ^- μ^+$. We introduce in the model the following dark particles: a neutral singlet Dirac-type lepton ($N$); two inert Higgs doublets ($η_{1,2}$), with one of which carrying a lepton number; a charged singlet dark scalar $(χ^+)$, and a singlet vector-like up-type dark quark ($T$). The first two entities are responsible for the radiative neutrino mass, and $χ^+$ couples to right-handed quarks and leptons and can resolve the tensions existing in muon $g-2$ and $B_s\to μ^- μ^+$. Furthermore, the BR of $B^+ \to K^+ ν\barν$ can be enhanced up to a factor of 2 compared to the SM prediction through the mediations of the dark $T$ and the charged scalars. In addition, we also study the impacts on the $K\to πν\barν$ 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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