Hiroyuki Nishiura, Takeshi Fukuyama
Assuming the Higgs triplet model, we obtain the bounds on the absolute neutrino mass and the unknown MNS parameters by measuring decay processes of doubly charged particles at the CERN LHC. Majorana CP violating phases affect the prediction rather seriously, which is served to restrict these phases.
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。
继续探索
We study the neutralino sector of the Minimal Non-minimal Supersymmetric Standard Model (MNSSM) where the $μ$ problem of the Minimal Supersymmetric Standard Model (MSSM) is solved without accompanying problems related with the appearance of domain walls. In the MNSSM as in the MSSM the lightest neutralino can be the absolutely stable lightest supersymmetric particle (LSP) providing a good candidate for the cold dark matter component of the Universe. In contrast with the MSSM the allowed range of the mass of the lightest neutralino in the MNSSM is limited. We establish the theoretical upper bou…
It is found that the seesaw mechanism not only explains the smallness of neutrino masses but also accounts for the large mixing angles simultaneously, even if the unification of the neutrino Dirac mass matrix with that of up-type quark sector is realized. In this mechanism, we show that the mixing matrix of the Dirac-type mass matrix gets extra rotations from the diagonalization of Majorana mass matrix. Assuming that the mixing angles to diagonalize the Majorana mass matrix are extremely small, we find that the large mixing angles of leptonic sector found in atmospheric and long baseline react…
The Left-Right symmetric extension of the Standard Model with Higgs isospin triplets can provide neutrino masses via a TeV scale seesaw mechanism. The doubly charged Higgs bosons H^{\pm\pm}_L and H^{\pm\pm}_R induce lepton flavour violating decays τ^\pm \to lll at tree-level via a coupling which is related to the Maki-Nakagawa-Sakata matrix (V_{\rm MNS}). We study the magnitude and correlation of τ^\pm \to lll and μ\to eγwith specific assumptions for the origin of the large mixing in V_{\rm MNS} while respecting the stringent bound for μ\to eee. It is also shown that an angular asymmetry for τ…
We study the thermal leptogenesis in the scenario where the standard model is extended to include one $SU(2)_{L}$ triplet Higgs boson, in addition to three generations of the right-handed neutrinos. And in the model we introduce the coupling between the Quintessence and the right-handed neutrinos, the triplet Higgs boson, so that the light neutrino masses vary during the evolution of the universe. Assuming that the lepton number asymmetry is generated by the decays of the lightest right-handed neutrino $N_{1}$, we find the thermal leptogenesis can be characterized by four model independent par…
We propose a supersymmetric A4 x SU(5) model of quasi-degenerate neutrinos which predicts the effective neutrino mass m_ee relevant for neutrinoless double beta decay to be proportional to the neutrino mass scale, thereby allowing its determination approximately independently of unknown Majorana phases. Such a natural quasi-degeneracy is achieved by using the A4 (as an example of a non-Abelian family symmetry with real triplet representations) to enforce a type II seesaw contribution to the neutrino mass matrix proportional to the identity. Tri-bimaximal neutrino mixing arises from a type I se…
Doubly charged Higgs bosons (H^++) are a distinctive signature of the Higgs Triplet Model of neutrino mass generation. If H^++ is relatively light (m_{H^++} < 400GeV) it will be produced copiously at the LHC, which could enable precise measurements of the branching ratios of the decay channels H^++ to l_i l_j. Such branching ratios are determined solely by the neutrino mass matrix which allows the model to be tested at the LHC. We quantify the dependence of the leptonic branching ratios on the absolute neutrino mass and Majorana phases, and present the permitted values for the channels ee, emu…
We study the stability constraints on the parameter space of a triplet extension of MSSM. Existence of unbounded from below directions in the potential can spoil successful Electroweak (EW) symmetry breaking by making the corresponding minimum unstable, and hence the model should be free from those directions. Avoiding those directions restricts the parameter space of the model. We derive four stability constraints, of which only three independent from each other. After scanning the model's parameter space for phenomenologically viable data points, we impose the stability constraints and find …
We model tri-bimaximal lepton mixing from first principles in a way that avoids the problem of the vacuum alignment characteristic of such models. This is achieved by using a softly broken A4 symmetry realized with an isotriplet fermion, also triplet under A4. No scalar A4-triplet is introduced. This represents one possible realization of general schemes characterized by the minimal set of either three or five physical parameters. In the three parameter versions mee vanishes, while in the five parameter schemes the absolute scale of neutrino mass, although not predicted, is related to the two …
We study the phenomenology of the type-II seesaw model at a linear e^-e^- collider. We show that the process e^-e^- \rightarrow alpha^-beta^- (alpha, beta = e, mu, tau being charged leptons) mediated by a doubly charged scalar is very sensitive to the neutrino parameters, in particular the absolute neutrino mass scale and the Majorana CP-violating phases. We identify the regions in parameter space in which appreciable collider signatures in the channel with two like-sign muons in the final state are possible. This includes Higgs triplet masses beyond the reach of the LHC.
In this study we investigate the phenomenological viability of the $Y=0$ Triplet Extended Supersymmetric Standard Model (TESSM) by comparing its predictions with the current Higgs data from ATLAS, CMS, and Tevatron, as well as the measured value of the $B_s\to X_s γ$ branching ratio. We scan numerically the parameter space for data points generating the measured particle mass spectrum and also satisfying current direct search constraints on new particles. We require all the couplings to be perturbative up to the scale $Λ_{\rm UV}=10^4$ TeV, by running them with newly calculated two loop beta f…
We study the textures of SM fermion mass matrices and their mixings in a supersymmetric adjoint SU(5) Grand Unified Theory with modular $S_4$ being the horizontal symmetry. The Yukawa entries of both quarks and leptons are expressed by modular forms with lower weights. Neutrino sector has an adjoint SU(5) representation 24 as matter superfield, which is a triplet of $S_4$. The effective light neutrino masses is generated through Type-III and Type-I seesaw mechanism. The only common complex parameter in both charged fermion and neutrino sectors is modulus $τ$. Down-type quarks and charged lepto…
Low Scale Leptogenesis in Singlet-Triplet Scotogenic Model
本研究在单态-三重态暗生模型中探索低标度轻子生成的可能性，通过引入三种具有特定质量等级的重费米子，将轻子生成标度降至TeV量级，同时可解释W玻色子质量异常，且能被中微子质量测量实验检验。
In this study we investigate the phenomenological viability of the $Y=0$ Triplet Extended Supersymmetric Standard Model (TESSM) by comparing its predictions with the current Higgs data from ATLAS, CMS, and Tevatron, as well as the measured value of the $B_s\to X_s γ$ branching ratio. We scan numerically the parameter space for data points generating the measured particle mass spectrum and also satisfying current direct search constraints on new particles. We require all the couplings to be perturbative up to the scale $Λ_{\rm UV}=10^4$ TeV, by running them with newly calculated two loop beta f…
We discuss the quark mass matrices in the $A_4$ modular symmetry, where the $A_4$ triplet of Higgs is introduced for each up-quark and down-quark sectors, respectively. The model has six real parameters and two complex parameters in addition to the modulus $τ$. By inputting six quark masses and three CKM mixing angles, we can predict the CP violation phase $δ$ and the Jarlskog invariant $J_{CP}$. The predicted ranges of $δ$ and $J_{CP}$ are consistent with the observed values. The absolute value of $V_{ub}$ is smaller than $0.0043$, while $V_{cb}$ is lager than $0.0436$. In conclusion, our qua…
We study the origin of neutrino mass through lepton-number violation and spontaneous $U(1)_{L_μ-L_τ}$ symmetry breaking. To accomplish the purpose, we include one Higgs triplet, two singlet scalars, and two vector-like doublet leptons in the $U(1)_{L_μ-L_τ}$ gauge extension of the standard model. To completely determine the free parameters, we employ the Frampton-Glashow-Marfatia (FGM) two-zero texture neutrino mass matrix as a theoretical input. It is found that when some particular Yukawa couplings vanish, an FGM pattern can be achieved in the model. Besides the explanation of neutrino data,…
Doubly-strange hidden-charm pentaquarks from the Fermi statistics of the light-quark cloud
将重子-粲偶素图像扩展到双奇异扇区，通过色磁标度和奇异质量增量预测了与K介子和反质子关联的五夸克态，其中两个与K介子关联的态形成近简并双重态。
In the minimal supersymmetric standard model (MSSM), when radiative corrections are included, the mass of the $CP=+1$ lightest Higgs boson is bounded by $\sim 110\ GeV$ for $m_t < 150\ GeV$ and a scale of supersymmetry breaking $\sim\ 1\ TeV$. In non-minimal supersymmetric standard models (NMSSM) upper bounds on the mass of the corresponding scalar Higgs boson arise if the theory is required to remain perturbative up to scales $\gg G_F^{-1/2}$. We have computed those bounds for two illustrative NMSSM: i) A model with an arbitrary number of gauge singlets; ii) A model with three $SU(2)_L$ tripl…
The triplet or type-II seesaw mechanism is the simplest way to endow neutrinos with mass in the Standard Model (SM). Here we review its associated theory and phenomenology, including restrictions from $S$, $T$, $U$ parameters, neutrino experiments, charged lepton flavour violations as well as collider searches. We also examine restrictions coming from requiring consistency of electroweak symmetry breaking, i.e. perturbative unitarity and stability of the vacuum. Finally, we discuss novel effects associated to the scalar mediator of neutrino mass generation namely, (i) rare processes, e.g. $l_α…
In this paper we consider a plausible scenario with conserved lepton number \textbf{$L=L_{e}-L_μ-L_τ$} within the framework of the exact solution of a particular 3-3-1 gauge model. We discuss what are the consequences of conserving this global leptonic symmetry from the viewpoint of the neutrino mass matrix constructed via special Yukawa terms (involving tensor products among Higgs triplets). We prove that the actual experimental data can naturally be reproduced by our scenario since soft breaking terms with respect to this lepton symmetry are properly introduced. As a consequence, our solutio…
The compelling experimental evidences for oscillations of solar, reactor, atmospheric and accelerator neutrinos imply the existence of 3-neutrino mixing in the weak charged lepton current. The current data on the 3-neutrino mixing parameters are summarised and the phenomenology of 3-$ν$ mixing is reviewed. The properties of massive Majorana neutrinos and of their various possible couplings are discussed in detail. Two models of neutrino mass generation with massive Majorana neutrinos - the type I see-saw and the Higgs triplet model, are briefly reviewed. The problem of determining the nature -…
Neutrino mixing parameters and masses from $Δ(96)\rtimes H_{CP}$ in the tri-direct CP approach
本研究在最小跷跷板模型中，利用三直接CP方法分析 $\Delta(96)\rtimes H_{CP}$ 的破缺模式，预测了正常和倒置顺序下的轻子混合模式（如TM1）及中微子质量，并给出了示例破缺模式的数值结果。
Using the type-II seesaw mechanism with three Higgs doublets phi_alpha (alpha = e, mu, tau) and four Higgs triplets, we build a model for lepton mixing based on a 384-element horizontal symmetry group, generated by the permutation group S_3 and by six Z_2 transformations. The charged-lepton mass matrix is diagonal; the symmetries of the model would require all the three masses m_alpha to be equal, but different vacuum expectation values of the phi_alpha allow the m_alpha to split. The number of parameters in the Majorana neutrino mass matrix m_nu depends on two options: full breaking of the pe…
We derive the lower bound on the absolute scale of lightest neutrino mass for normal hierarchy and inverted hierarchy pattern of light neutrinos by studying the new physics contributions to charged lepton flavour violations in the framework of a TeV scale left-right symmetric model. In the model, the fermion sector comprises the usual quarks and leptons plus a fermion singlet per generation and the scalar sector consists of isospin doublets, triplets and a bidoublet. The framework allows large light-heavy neutrino mixing where the light neutrino mass formula is governed by a natural type-II se…
In the context of top-quark condensation models, the top-quark alone is too light to saturate the correct value of the electroweak scale by its condensate. Within the seesaw scenario the neutrinos can have their Dirac masses large enough so that their condensates can provide significant contribution to the value of the electroweak scale. We address the question of a phenomenological feasibility of the top-quark and neutrino condensation conspiracy against the electroweak symmetry. Mandatory is to reproduce the masses of electroweak gauge bosons, the top-quark mass and the recently observed sca…
Topological Integer-Winding Dark Matter with a Dark Higgs Triplet: Stability from $π_2(\mathrm{SU}(3)/\mathrm{SO}(3)) = \mathbb{Z}$
提出基于 SU(3)_dark→SO(3)_dark×Z_2 破缺产生拓扑稳定暗物质的模型，预言质量比与引力波信号，可被 FCC-ee 和 LISA 检验。
Non-holomorphic Modular $S_4$ Lepton Flavour Models
基于非超对称模不变性方法，采用有限模群 S4 作为味对称群，构建了所有 7 参数和 8 参数轻子味模型，预测了中微子质量、CP 破坏相位等，并证明这些模型均可通过现象学测试证伪。
The neutrino mass and dark matter (DM) problems are addressed in a Standard Model extension where the type-II seesaw and scotogenic mechanisms coexist. The model features a flavour $\mathcal{Z}_8$ discrete symmetry which is broken down to a $\mathcal{Z}_2$, stabilising the (scalar or fermion) DM particle. Spontaneous CP violation is implemented through the complex vacuum expectation value of a singlet scalar field, inducing observable CP-violating effects in the lepton sector. The structure of the effective neutrino mass matrix leads to constraints on the low-energy neutrino observables, namel…
Investigating two-zero texture in the light of gauged Type-II seesaw
本文系统分析中微子质量矩阵双零纹理对CP相位及有效马约拉纳质量的影响，并展示其在规范Type-II跷跷板模型中的自然实现及现象学后果。
Deviations from $μ$-$τ$ symmetry using $Δ$(27) group on neutrino masses and mixings
本研究构建基于Δ(27)离散味对称性的I型跷跷板中微子质量模型，通过扩展标准模型粒子内容实现μ-τ对称性偏离，其振荡参数、质量和与实验及宇宙学数据吻合，并给出两类质量等级下的有效质量、CP破坏及重子不对称度预言。
We present a detailed discussion on neutrinoless double beta decay within a class of left-right symmetric models where neutrino mass originates by natural type-II seesaw dominance. The spontaneous symmetry breaking is implemented with doublets, triplets and bidoublet scalars. The fermion sector is extended with an extra sterile neutrino per generation that helps in implementing the seesaw mechanism. The presence of extra particles in the model exactly cancels type-I seesaw and allows large value for Dirac neutrino mass matrix $M_D$. The key feature of this work is that all the physical masses …
扫码添加微信好友，提出您的宝贵建议 👇
💡 备注请填写：网站反馈
发表机构由 AI 从论文文本抽取，如发现错误，欢迎反馈修正建议。