We introduce three right-handed neutrinos and three sterile neutrinos, and consider an inverse seesaw mechanism for neutrino mass generation. From naturalness point of view, their Majorana masses should be small, while it induces a large neutrino Yukawa coupling. Then, a neutrinoless double beta decay rate can be enhanced, and a sizable Higgs mass correction is inevitable. We find that the enhancement rate can be more than ten times compared with a standard prediction from light neutrino contribution alone, and an analytic form of heavy neutrino contributions to the Higgs mass correction. In addition, we numerically analyze the model, and find almost all parameter space of the model can be complementarily searched by future experiments of neutrinoless double beta decay and $μ\to e$ conversion.
In this paper, we search for conditions that the mass matrix of light neutrinos $m_ν$ is not a result of large cancellations for the type-I seesaw mechanism with four-zero texture. For the Yukawa matrix of neutrinos $Y_ν$ and heavy Majorana mass matrix $M_{R}$, these conditions are written as $(Y_ν)_{i2} \propto (m_ν)_{i2} \, \Rightarrow \, (Y_ν)_{i2} \propto (M_{R})_{i2}$. We call them {\it alignment} conditions because they align the certain rows or columns of the three neutrino mass matrices. If these conditions do not hold, the large mixing in $m_ν$ is a result of fine-tuning due to the ca…
We show that the observed anomalies in the lepton sector can be explained in extensions of the Standard Model that are natural and, therefore, resolve the Higgs sector hierarchy problem. The scale of new physics is around the TeV and Technicolor-like theories are ideal candidate models.
Lepton flavor violation and non-unitary lepton mixing in low-scale type-I seesaw
在低尺度的跷跷板机制中，例如逆跷跷板和线性跷跷板，人们期望（i）潜在的大轻子味破坏（LFV）和（ii）相当大的非标准中微子相互作用（NSI）。我们考虑轻子混合矩阵中的非么正效应的大小之间的相互作用，以及实验室中LFV搜索的约束条件。我们发现，NSI参数可以是相当大的，在某些情况下高达百分比水平，而LFV率，如μ-> e γ，位于当前的限制，包括最近由MEG合作组设置。因此，即将到来的长基线中微子实验为补充LFV和弱普适性测试提供了一个机会窗口。
Non-unitarity of the leptonic mixing matrix in the TeV-scale type-I seesaw model
轻子味混合中的非么正性效应被认为是I型跷跷板模型的一般特征之一。因此，我们探讨了这些影响TeV规模的I型跷跷板模型，并表明存在非平凡的相关性之间的非么正性参数，源于典型的风味结构的低规模的跷跷板模型。一般来说，从分析讨论和数值结果可以看出，所有六个非么正性参数都与三个模型参数有关，而广泛研究的参数η e τ和η μ τ不是唯象意义的
We propose a model for the vector-like lepton to explain the small muon mass by a seesaw mechanism, based on lepton-specific two Higgs doublet models with a local $U(1)'$ symmetry. There is no bare muon mass for a nonzero $U(1)'$ charge of the leptophilic Higgs doublet, so the physical muon mass is generated due to the mixing between the vector-like lepton and the muon after the leptophilic Higgs doublet and the dark Higgs get VEVs. In this scenario, the non-decoupling effects of the vector-like lepton give rise to leading contributions to the muon $g-2$, thanks to the light $Z'$ and the light…
Distinguishing seesaw models at LHC with multi-lepton signals
我们研究了LHC发现电弱尺度重中微子单线态（跷跷板I）、标量三线态（跷跷板II）和费米子三线态（跷跷板III）的可能性。对于跷跷板I，我们考虑一个重马约拉纳中微子耦合到电子或μ子。对于跷跷板II，我们集中讨论新标量衰变为两个轻子的可能情形。对于跷跷板III，我们仅限于重马约拉纳费米子三重态衰变为轻轻子加规范或希格斯玻色子，除了不自然的小混合外，它们占主导地位。根据带电轻子多重性对可能的信号进行了分类，研究了从1到6个带电轻子的9种不同的终态。用快速探测器模拟信号和背景，发现三轻子通道l ~+- l ~+- l ~+是目前发现标量三重态的最佳通道，而对于费米子三重态，它与类号双轻子通道l ~+- l ~+-一样好。对于质量为O（100）GeV的重中微子，这种三轻子通道也优于通常研究的类号双轻子模式。除了评估发现的潜力，我们特别强调的歧视之间的跷跷板模型，如果观察到一个积极的信号。这不仅可以通过搜索不同最终状态的信号来实现，还可以通过重建质量并确定新共振的电荷来实现，这在几种情况下都是可能的。对于高光度，进一步的证据是通过分析在最干净的通道与三个或四个轻子的生产角分布。
We suggest a low-scale model based on $A_4\times Z_4 \times Z_2$ symmetry and a global lepton number $U(1)_L$ symmetry capable of generating the current neutrino data. The neutrino mass smallness is reproduced by the linear seesaw mechanism. The model can explain the current observed pattern of lepton mixing in which the reactor and atmospheric angles get the best-fit values, and the solar angle and Dirac phase lie within $3σ$ limits. The obtained values of the sum of neutrino mass and the effective neutrino mass are below the present experimental limits.
TeV Scale Inverse Seesaw in SO(10) and Leptonic Non-Unitarity Effects
我们表明，TeV尺度的中微子质量的反跷跷板模型可以实现的框架内的超对称SO（10）模型符合规范耦合统一和观察到的中微子质量和混合。我们提出了我们对轻子混合矩阵中的非么正性效应的期望，其中一些是在未来的中微子工厂中可以观察到的，以及下一代对轻子味道违反过程（如μ-> e + γ）的搜索。该模型具有TeV量级的W_R和Z'玻色子，可以在大型强子对撞机上得到。
Leptonic Flavor Structure in the Brane Shifted Extra Dimensional Seesaw Mechanism
本文讨论了体中有一个右手中微子的膜移额外维跷跷板模型产生的轻子味结构。与以前的工作相比，没有酉近似的$3 \times 3$子矩阵已被采用。这使得研究现象学的签名，如轻子味道违反衰变。假设CP守恒，该模型的一个强有力的预测是味违反带电轻子衰变和Z衰变的分支比的比值，它与中微子混合角和中微子质量等级有关。此外，它是可能的，以获得分支比$μ\rightarrow e γ$接近的实验界限，即使与汤川耦合一阶。
