论文标题
$（g-2）_μ$和koto异常的轻标量解释
A Light Scalar Explanation of $(g-2)_μ$ and the KOTO Anomaly
论文作者
论文摘要
The KOTO experiment has recently performed a search for neutral Kaons decaying into neutral pions and a pair of neutrinos. Three events were observed in the KOTO signal region, with an expected background of about 0.05.由于未发现系统错误的明确信号，因此衰减$ k_ {l} \rightArrowπ^0ν\barν$中的事件过剩很有趣。 One possibility to explain this anomaly would be the presence of a scalar $ϕ$ with mass of the order of the pion mass and inducing decays $K_L \to π^0 ϕ$ which mimic the observed signal.A scalar with mass of the order of the pion mass and a coupling to muons of the order of the Standard Model Higgs coupling could also explain the muon anomalous magnetic moment anomaly $(g-2)_μ$.我们基于这些事实，以表明与叶子和夸克具有耦合的轻单元标量，因为在两个Higgs Doublet模型中与希格斯态混合而引起的句子可能会导致对这两个异常的解释。更具体地说，我们表明在所谓的type-X型号中，这种情况是这种情况，在该模型中，leptons和Quarks将它们夫妇搭配到两个不同的Higgs Doublet，而标量质量在40至70 MeV之间。由于适合$（G-2）_ $所需的钩子的耦合相对较大，因此标量寿命意外落入了次纳秒范围，这对于逃避严重的质子束转储实验和天体物理的约束至关重要，尽管它对电子束束缚实验的约束变得敏感。 The additional phenomenological properties of this model are discussed.
The KOTO experiment has recently performed a search for neutral Kaons decaying into neutral pions and a pair of neutrinos. Three events were observed in the KOTO signal region, with an expected background of about 0.05. Since no clear signal of systematic errors have been found, the excess of events in the decay $K_{L}\rightarrowπ^0ν\barν$ is quite intriguing. One possibility to explain this anomaly would be the presence of a scalar $ϕ$ with mass of the order of the pion mass and inducing decays $K_L \to π^0 ϕ$ which mimic the observed signal.A scalar with mass of the order of the pion mass and a coupling to muons of the order of the Standard Model Higgs coupling could also explain the muon anomalous magnetic moment anomaly $(g-2)_μ$. We built on these facts to show that a light singlet scalar with couplings to the leptons and quarks as the ones induced by mixing with Higgs states in two Higgs doublet models may lead to an explanation of both anomalies. More specifically, we show that this is the case in the so-called type-X models in which leptons and quarks couple to two different Higgs doublets, and for scalar masses that are in the range between 40 and 70 MeV. Due to the relatively large coupling to leptons required to fit $(g-2)_μ$, the scalar lifetime accidentally falls into the sub-nanosecond range which is essential to evade the severe proton beam dump experiments and astrophysical constraints, though it becomes sensitive to constraints from electron beam dump experiments. The additional phenomenological properties of this model are discussed.
