We propose a new kind of inverse seesaw model without any additional symmetries. Instead of the symmetries, we introduce several fermions and bosons with higher $SU(2)_L$ representations. After formulating the Higgs sector and neutrino sector, we show that the cut-off energy, which is valid to our model, is at around TeV scale, by examining behavior of $SU(2)_L$ gauge coupling. Then we show the testability of our model at collider physics.
TeV-scale seesaw mechanisms are interesting due to their potential testability at existing collider experiments. Herein we propose an E$_6$-inspired model allowing a TeV-scale pseudo-Dirac singlet neutrino seesaw mechanism with naturally sizeable Yukawa couplings of $\mathcal{O}(10^{-2})$. The model also contains new U(1) gauge interactions (and associated $Z^\prime$ bosons with which the singlet neutrinos can be produced at colliders), typically long-lived colour triplet fermions, SU(2) doublet fermions, and a complex scalar - potentially all at the TeV-scale. Additionally we identify three p…
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
The appealing feature of inverse seesaw models is that the Standard Model (SM) neutrino mass emerges from the exchange of TeV scale singlets with sizable Yukawa couplings, which can be tested at colliders. However, the tiny Majorana mass splitting between TeV singlets, introduced to accommodate small neutrino masses, is left unexplained. Moreover, we argue that these models suffer from a structural limitation that prevents a successful leptogenesis if one insists on having unsuppressed Yukawa couplings and TeV scale singlets. In this work we propose a hybrid seesaw model, where we replace the …
We propose an inverse seesaw model with large $SU(2)_L$ multiplet fields which realizes natural mass hierarchies among neutral fermions. Here, lighter neutral fermion mass matrices are induced via two suppression mechanisms; one is small vacuum expectation value of $SU(2)_L$ triplet required by rho parameter constraint and the other is generation of Majorana mass term of extra singlet fermions at one-loop level. To realize the loop masses, we impose $Z_2$ symmetry which also guarantees stability of a dark matter candidate. Furthermore, we discuss anomalous magnetic moment and collider physics …
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。
We build a renormalizable theory where the inverse seesaw mechanism explains the pattern of SM fermion masses. To the best of our knowledge, our model corresponds to the first implementation of the inverse seesaw mechanism for the charged fermion sector. In our theory, the inverse seesaw mechanism is implemented at the tree and one-loop levels in order to generate the masses for the second and first families of the SM charged fermions, respectively. The third family of SM charged fermions obtain tree-level masses from the Higgs doublets $ϕ_{1}$ (for the top quark) and $ϕ_{2}$ (for the bottom q…
We develop a model of sneutrino inflation that is charged under $U(1)_{B-L}$ gauge symmetry in no-scale supergravity framework. The model provides an interesting modification of tribrid inflation. We impose $U(1)_R$ symmetry on the renormalizable level while allow Planck suppressed non-renormalizable operators that break R-symmetry. This plays a crucial role in realizing a Starobinsly-like inflation scenario from one hand. On the other hand it plays essential role, as well as SUSY breaking effects, in deriving the neutrino masses from TeV inverse seesaw mechanism. Thus we provide an interpreta…
We develop an extension of the basic inverse seesaw model which addresses simultaneously two of its drawbacks, namely, the lack of explanation of the tiny Majorana mass term $μ$ for the TeV-scale singlet fermions and the difficulty in achieving successful leptogenesis. Firstly, we investigate systematically leptogenesis within the inverse (and the related linear) seesaw models and show that a successful scenario requires either small Yukawa couplings, implying loss of experimental signals, and/or quasi-degeneracy among singlets mass of different generations, suggesting extra structure must be …
Very recently a novel implementation of type-II seesaw mechanism for neutrino mass has been proposed in SU(5) grand unified theory with a number of desirable new physical phenomena beyond the standard model.Introducing heavy right-haded neutrinos and extra fermion singlets, in this work we show how the type-I seeaw cancellation mechanism works in this SU(5) framework. Besides predicting verifiable LFV decays, we further show that the model predicts dominant double beta decay with normal hierarchy or inverted hierarchy of active light neutrino masses in concordance with cosmological bound. In a…
By extending the Standard Model with singlet-doublet fermions and triplet scalars, all odd under a new $Z_2$ symmetry, we introduce a radiative seesaw model that can simultaneously account for dark matter, explain the existence of neutrino masses and allow for gauge coupling unification. We explore the viable parameter space of the model after imposing collider, Higgs mass, dark matter, neutrino mass and lepton flavour violation constraints. We find that dark matter in this model is fermionic for masses below about 1 TeV and scalar above and observe a high degree of complementarity between dir…
Inverse seesaw is a genuine TeV scale seesaw mechanism. In it active neutrinos with masses at eV scale requires lepton number be explicitly violated at keV scale and the existence of new physics, in the form of heavy neutrinos, at TeV scale. Therefore it is a phenomenologically viable seesaw mechanism since its signature may be probed at the LHC. Moreover it is successfully embedded into gauge extensions of the standard model as the 3-3-1 model with the right-handed neutrinos. In this work we revisit the implementation of this mechanism into the 3-3-1 model and employ deep learning analysis to…
We investigate the collider phenomenology of the scalar triplet particles in the Type-II seesaw model at a 100 TeV $pp$ collider. Depending on triplet vacuum expectation value $v_Δ$, the dominant discovery channels could be $H^{++} H^{--}$ and $H^{\pm\pm}H^\mp$. We find the $H^{\pm\pm}H^\mp\to W^\pm W^\pm h W^\mp/\ell^\pm \ell^\pm h W^\mp$ channels are promising for both model discovery at relatively large $v_Δ$ and determination of the Higgs portal couplings $λ_4$ and $λ_5$. We also find that these two channels are complementary to indirect determination of $λ_4$ from future precise measureme…
Explaining the tiny neutrino masses and non-zero mixings have been one of the key motivations for going beyond the framework of the Standard Model (SM). We discuss a collider testable model for generating neutrino masses and mixings via radiative seesaw mechanism. That the model does not require any additional symmetry to forbid tree-level seesaws makes its collider phenomenology interesting. The model includes multi-charged fermions/scalars at the TeV scale to realize the Weinberg operator at 1-loop level. After deriving the constraints on the model parameters resulting from the neutrino osci…
