We analyze the potential of Compact Linear Colliders (CLIC) based on the γe − collisions to search for the radion in the Randall -Sundrum (RS) model, where compactification radius of the extra dimension is stabilized by the radion, which is a scalar field lighter than the graviton Kaluza-Klein states. The radion production in the high energy γe − colliders with the polarization of the electron beams are calculated in detail. Numerical evaluation shows that if the radion mass is not too heavy with the mass order of GeV then the reaction can give observable cross section in future colliders at the high degree of polarization.

The lepton flavor violating decay of the Standard Model-like Higgs boson (LFVHD), h → µτ , is discussed in seesaw models at the one-loop level. Based on particular analytic expressions of Passarino-Veltman functions, the two unitary and 't Hooft Feynman gauges are used to compute the branching ratio of LFVHD and compare with results reported recently. In the minimal seesaw (MSS) model, the branching ratio was investigated in the whole valid range 10 −9 −10 15 GeV of new neutrino mass scale m n 6 . Using the Casas-Ibarra parameterization, this branching ratio enhances with large and increasing m n 6 . But the maximal value can reach only order of 10 −11 . Interesting relations of LFVHD predicted by the MSS and inverse seesaw (ISS) model are discussed. The ratio between two LFVHD branching ratios predicted by the ISS and MSS is simply m 2 n 6 µ −2 X , where µ X is the small neutrino mass scale in the ISS. The consistence between different calculations is shown precisely from analytical approach.

We calculate the symmetry factors of diagrams for real and complex scalar fields in general form using an analysis of the Wick expansion for Green's functions. We separate two classes of symmetry factors: factors corresponding to connected diagrams and factors corresponding to vacuum diagrams. The symmetry factors of vacuum diagrams play an important role in constructing the effective action and phase transitions in cosmology. In the complex scalar field theory, diagrams with different topologies can contribute the same, and the inverse symmetry factor for the total contribution is therefore the sum of the inverse symmetry factors.

We perform a comprehensive analysis of several phenomenological aspects of the renormalizable extension of the inert 3-3-1 model with sequentially loop-generated SM fermion mass hierarchy. Special attention is paid to the study of the constraints arising from the experimental data on the ρ parameter, as well as those ones resulting from the charged lepton flavor violating process µ → eγ and dark matter. We also study the single Z production via Drell-Yan mechanism at the LHC. We have found that Z gauge bosons heavier than about 4 TeV comply with the experimental constraints on the oblique ρ parameter as well as with the collider constraints. In addition, we have found that the constraint on the charged lepton flavor violating decay µ → eγ sets the sterile neutrino masses to be lighter than about 1.12 TeV. arXiv:1810.00605v2 [hep-ph] 10 Jun 2019 In addition the model allows charged lepton flavor violating processes within reach of the forthcoming experiments. The scalar potential and the gauge sector of the model are analyzed and discussed in detail. Our model successfully accommodates the observed Dark matter relic density. PACS numbers: 12.60.Cn,12.60.Fr Keywords: Extensions of electroweak gauge sector, Extensions of electroweak Higgs sector I. INTRODUCTION Despite its great successes, the Standard Model (SM) does not explain the observed mass and mixing hierarchies in the fermion sector, which remain without a compelling explanation.It is known that in the SM, the masses of the matter fields are generated from the Yukawa interactions. In addition, the CKM quark mixing matrix is also constructed from the same Yukawa couplings. To solve these puzzles, some mechanisms have been proposed. To the best of our knowledge, the first attempt to explain the huge differences in the SM fermion masses is the Froggatt -Nielsen (FN) mechanism [1]. According to the FM mechanism, the mass differences between generations of fermions arise from suppression factors depending on the FN charges of the particles. It has been noticed that in order to implement the aforementioned mechanism, the effective Yukawa interactions have to be introduced, thus making this theory non-renormalizable. From this point of view, the recent mechanism proposed by Cárcamo, Kovalenko and Schmidt [2] (called by CKS mechanism) based on sequential loop suppression mechanism, is more natural since its suppression factor arises from the loop factor l ≈ (1/4π) 2 .One of the main purposes of the models based on the gauge group SU (3) C × SU (3) L × U (1) X (for short, 3-3-1 model) [3][4][5][6][7][8][9][10] is concerned with the search of an explanation for * Electronic address:

We investigate the vacuum stability conditions of theSupersymmetric reduced minimal 331 model (SUSYRM331) that createimportant  consequences on  Higgs mass spectrum as well assoft-parameters of the model. We prove that if this condition issatisfied then all Higgses are massive. Furthermore,soft-parameters should be in order of \(SU(3)_L\) scale. Based onthis, we investigate in detail masses of CP-even neutral  anddoubly charged Higgses in the model. The  neutral Higgs sectorincludes one light Higgs with mass at tree level \(m_{H^0_1}\simeq m_Z|\cos 2\gamma | < 92.0\) GeV and three other heavy Higgses. Fordoubly charged Higgses, there may exist a light Higgs which can beobserved by recent colliders such as LHC.