Under a hypothesis of classically conformal theories, we investigate the minimal B-L extended Standard Model, which naturally provides seesaw mechanism for explaining tiny neutrino masses. In this setup, radiative gauge symmetry breaking is successfully realized in very simple way: The broken through anomaly induced by quantum corrections Coleman-Weinberg potential. Associated with breaking, Higgs mass parameter dynamically generated, electroweak triggered. We find that wide range space can...

In a previous paper [S. Iso, N. Okada, and Y. Orikasa, Phys. Lett. B 676, 81 (2009).], we have proposed the minimal $B\ensuremath{-}L$ extended standard model as phenomenologically viable that realizes Coleman-Weinberg-type breaking of electroweak symmetry. Assuming classical conformal invariance stability up to Planck scale, will show in this naturally predicts TeV scale well light standard-model singlet Higgs boson right-handed neutrinos around same energy scale. We also study...

We propose a one-loop induced radiative seesaw model applying modular $S_3$ flavor symmetry, which is known as the minimal non-Abelian discrete group. In this scenario, dark matter (DM) candidate correlated with neutrinos and lepton violations (LFVs). show several predictions of mixings phases satisfying LFVs, observed relic density, neutrino oscillation data.

We explore the idea of accidental dark matter (aDM) stability in scale invariant local $U(1{)}_{B\ensuremath{-}L}$ model, which is a theory for neutrino and at same time radiatively breaks invariance via quantum mechanical dynamics sector. A real singlet scalar can be DM with an ${Z}_{2}$, by virtue both extended symmetries. charged complex also viable due to (or remanent) ${Z}_{3}$. They reproduce correct relic density annihilations through conventional Higgs portal or portal. The scenario...

The recent discovery of a Higgs-like particle at around 126 GeV has provided big hint towards the origin Higgs potential. In particular, running quartic coupling vanishes near Planck scale, which indicates possible link between physics in electroweak and scales. Motivated by this hierarchy problem, we investigate possibility that flat potential scale. study renormalization group analysis B − L (baryon number minus lepton number) extension standard model [1,2] with classical conformality....

We study the neutrino sector in a minimal $SU(3)_L\times U(1)_X$ model, which its mass is generated at one-loop level with charged lepton mass, and hence there exists strong correlation between charged-lepton mass. identify parameter region of this model to satisfy current oscillation data as well constraints on flavor violating processes. also discuss possibility explain muon anomalous magnetic moment.

When the classically conformal invariance is imposed on minimal gauged B-L extended Standard Model (SM), gauge symmetry broken by Coleman-Weinberg mechanism naturally at TeV scale. Introducing a new Z_2 parity in model, we investigate phenomenology of right-handed neutrino dark matter whose stability ensured parity. We find that relic abundance particle can be consistent with observations through annihilation processes enhanced resonances either SM Higgs boson, boson or (Z' boson)....

We investigate the resonant leptogenesis scenario in minimal $B\ensuremath{-}L$ extended standard model with symmetry breaking at TeV scale. Through detailed analysis of Boltzmann equations, we show how much resultant baryon asymmetry via is enhanced or suppressed, depending on parameters, particular, neutrino Dirac-Yukawa couplings and scale Majorana masses heavy degenerate neutrinos. In order to consider a realistic case, impose simple ansatz for parameters analyze oscillation as function...

We investigate a possibility of the ``flatland scenario,'' in which electroweak gauge symmetry is radiatively broken via Coleman-Weinberg mechanism starting from completely flat Higgs potential at Planck scale. show that flatland scenario realizable only when an inequality $K<1$ among coefficients $\ensuremath{\beta}$ functions satisfied. several models satisfying condition.

We study a non-holomorphic modular $S_3$ flavor symmetry in which we analyze neutrino sector, dark matter, and lepton violations. The active mass is generated via one-loop level. achieve chi-square analysis demonstrate some predictions cases of normal hierarchy with fermionic or bosonic matter inverted matter.

We study a Zee-Babu neutrino model in non-holomorphic modular $A_4$ symmetry, and we construct so that there are minimum free parameters (two complex parameters). find only the normal hierarchy is allowed. Moreover, allowed region to satisfy oscillation data localized at nearby $\tau=\omega$. The small absolute deviation plays crucial role fitting two mixings of $s^2_{23}$ $s^2_{12}$. In addition, obtain several predictions on Majorana Dirac CP phases, neutrinoless double beta decay as shown...

We investigate a radiative electroweak gauge symmetry breaking scenario via the Coleman-Weinberg mechanism starting from completely flat Higgs potential at Planck scale (``flatland scenario''). In our previous paper, we showed that flatland is possible only when an inequality $K<1$ among coefficients of $\ensuremath{\beta}$ functions satisfied. this calculate number $K$ in various models with extra $U(1)$ sector addition to standard model particles. also show renormalization group behaviors...

We study a three-loop induced neutrino model with global $U(1)$ symmetry at TeV scale, in which we naturally accommodate bosonic dark matter candidate. discuss the allowed regions of masses and quartic couplings for charged scalar bosons as well mass on analogy original Zee-Babu model, show difference between them. also possibility collider searches, future like-sign electron liner could be promising.

We propose a three loop radiative neutrino mass scenario with an isolated doubly charged singlet scalar ${k}^{\ifmmode\pm\else\textpm\fi{}\ifmmode\pm\else\textpm\fi{}}$ without couplings to the leptons, while two other singly scalars ${h}_{1}^{\ifmmode\pm\else\textpm\fi{}}$ and ${h}_{2}^{\ifmmode\pm\else\textpm\fi{}}$ attach them. In this setup, lepton flavor violation originating from exchanges is suppressed model less constrained, where some can take sizable values. As reported in our...

We study a three loop induced radiative neutrino model with global $U(1)$ symmetry at TeV scale, in which we consider two component dark matter particles. discuss the possibility to explain X-ray line signal about 3.55 keV recently reported by XMN-Newton observatory using data of various galaxy clusters and Andromeda galaxy. Subsequently, also show that sizable muon anomalous magnetic moment, discrepancy effective number species $\Delta N_{\rm eff}\approx$ 0.39, scattering cross section...

We investigate a possibility for explaining the recently announced 750\,GeV diphoton excess by ATLAS and CMS experiments at CERN LHC in model with multiple doubly charged particles, which was originally suggested tiny neutrino masses through three-loop effect natural way. The enhanced radiatively generated effective coupling of new singlet scalar $S$ particles loop enlarges production rate $pp\to S+X$ via photon fusion process also decay width $\Gamma(S\to \gamma\gamma)$ even without...

Classical scale invariance (CSI) may be one of the solutions for hierarchy problem. Realistic models electroweak symmetry breaking based on CSI require extended scalar sectors without mass terms, and is broken dynamically at quantum level by Coleman–Weinberg mechanism. We discuss discriminative features these models. First, using experimental value discovered Higgs boson h(125), we obtain an upper bound lightest additional (≃543 GeV), which does not depend its isospin hypercharge. Second, a...

We study one-loop induced radiative seesaw model applying a modular $A_4$ flavor symmetry, in which the neutrino mass matrix is achieved by two different Yukawa couplings one of also contributes to positive value muon anomalous magnetic moment as well lepton violations. Thanks specific via symmetry and its weight, we find several predictions for sector through our numerical analysis.

Effects of Kaluza-Klein excited neutral vector bosons ($Z'$ bosons) in the gauge-Higgs unification on $e^+e^- \to \bar{q}q, \ell^+\ell^-$ cross sections are studied, particularly future $e^+ e^-$ collider experiments with polarized beams. Significant deviations energy and polarization dependence $\sigma(\mu^+\mu^-)$, lepton forward-backward asymmetry, $R_b(\mu) \equiv \sigma(\bar{b}b)/\sigma(\mu^+\mu^-)$ left-right asymmetry from standard model predicted.

We propose a predictive lepton model under modular $S_4$ symmetry, where the neutrino mass matrix arises from radiative seesaw at one-loop level. The tree-level is forbidden by well-assigned weights, which also play an important role in stabilizing dark matter candidate due to remnant $Z_2$ symmetry even after breaking symmetry. Supposing three families of Majorana neutrinos, right-handed charged-leptons and left-handed be embedded respectively into singlet, doublet, triplet $S_4$, we obtain...

General U(1) extension of the Standard Model (SM) is a well motivated beyond Model(BSM) scenario where three generations right handed neutrinos (RHNs) are introduced to cancel gauge and mixed gauge-gravity anomalies. After U(1)X broken, RHNs participate in seesaw mechanism generate light neutrino masses satisfying oscillation data. In addition that, neutral boson Z′ evolved which interacts with left fermions differently manifesting chiral nature model could be probed future collider...

Abstract The origin of tiny neutrino mass is an unsolved puzzle leading to a variety phenomenological aspects beyond the Standard Model (BSM). We consider U (1) gauge extension (SM) where so-called seesaw mechanism incarnated with help thee generations Majorana type right-handed neutrinos followed by breaking and electroweak symmetries providing anomaly free structure. In this framework, neutral BSM boson $$Z^\prime $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msup>...

Signatures of the $\mathrm{SO}(5)\ifmmode\times\else\texttimes\fi{}\mathrm{U}(1)$ gauge-Higgs unification at LHC and future colliders are explored. The Kaluza-Klein (KK) mass spectra $\ensuremath{\gamma},Z,{Z}_{R}$ Higgs self-couplings obey universality relations with Aharonov-Bohm phase ${\ensuremath{\theta}}_{H}$ in fifth dimension. current data low energies indicate ${\ensuremath{\theta}}_{H}<0.2$. Couplings quarks leptons to KK gauge bosons determined. Three neutral bosons, first modes...