Handed Majorana Neutrino Research Articles

INFLATION AND AXION DARK MATTER IN THE 3-3-1 MODEL

We consider a renormalizable theory, which successfully explains the number of Standard Model(SM) fermion families and whose non-SM scalar sector includes an axion dark matter as well asa field responsible for cosmological inflation. In such theory, the axion gets its mass via radiativecorrections at one-loop level mediated by virtual top quark, right handed Majorana neutrinos andSM gauge bosons. Its mass is obtained in the range 4 keV÷ 40 keV, consistent with the onepredicted by XENON1T experiment, when the right handed Majorana neutrino mass is varied from100 GeV up to 350 GeV, thus implying that the light active neutrino masses are generated from a lowscale type I seesaw mechanism. Furthermore, the theory under consideration can also successfullyaccommodates the XENON1T excess provided that the PQ symmetry is spontaneously broken atthe 1010 GeV scale.PACS numbers: 11.30.Fs, 12.15.Ff, 12.60.-i

Fermion masses and mixings and g-2 muon anomaly in a 3-3-1 model with D_4 family symmetry

We propose a predictive model based on the SU(3)_Ctimes SU(3)_Ltimes U(1)_X gauge symmetry, which is supplemented by the D_4 family symmetry and several auxiliary cyclic symmetries whose spontaneous breaking produces the observed SM fermion mass and mixing pattern. The masses of the light active neutrinos are produced by an inverse seesaw mechanism mediated by three right handed Majorana neutrinos. To the best of our knowledge the model corresponds to the first implementation of the D_4 family symmetry in a SU(3)_Ctimes SU(3)_Ltimes U(1)_X theory with three right handed Majorana neutrinos and inverse seesaw mechanism. Our proposed model successfully accommodates the experimental values of the SM fermion mass and mixing parameters, the muon anomalous magnetic moment as well as the Higgs diphoton decay rate and meson oscillations constraints. The consistency of our model with the muon anomalous magnetic moment requires charged exotic vector like leptons at the TeV scale.

A renormalizable left-right symmetric model with low scale seesaw mechanisms

We propose a low scale renormalizable left-right symmetric theory that successfully explains the observed SM fermion mass hierarchy, the tiny values for the light active neutrino masses and is consistent with the lepton and baryon asymmetries of the Universe, the muon and electron anomalous magnetic moments as well as with the constraints arising from the meson oscillations. In the proposed model the top and exotic quarks obtain masses at tree level, whereas the masses of the bottom, charm and strange quarks, tau and muon leptons are generated from a tree level Universal Seesaw mechanism, thanks to their mixings with the charged exotic vector like fermions. The masses for the first generation SM charged fermions arise from a radiative seesaw mechanism at one loop level, mediated by charged vector like fermions and electrically neutral scalars. The light active neutrino masses are produced from a one-loop level inverse seesaw mechanism mediated by electrically neutral scalar singlets and right handed Majorana neutrinos. Our model is also consistent with the experimental constraints arising from the Higgs diphoton decay rate as well as with the constraints arising from charged lepton flavor violation. We also discuss the Z′ and heavy scalar production at a proton-proton collider.

Collider signatures of vector-like fermions from a flavor symmetric model

We propose a model with two Higgs doublets and several SU(2) scalar singlets with a global non-Abelian flavor symmetry {mathcal{Q}}_6times {mathcal{Z}}_2 . This discrete group accounts for the observed pattern of fermion masses and mixing angles after spontaneous symmetry breaking. In this scenario only the third generation of fermions get their masses as in the Standard Model (SM). The masses of the remaining fermions are generated through a seesaw-like mechanism. To that end, the matter content of the model is enlarged by introducing electrically charged vector-like fermions (VLFs), right handed Majorana neutrinos and several SM scalar singlets. Here we study the processes involving VLFs that are within the reach of the Large Hadron Collider (LHC). We perform collider studies for vector-like leptons (VLLs) and vector-like quarks (VLQs), focusing on double production channels for both cases, while for VLLs single production topologies are also included. Utilizing genetic algorithms for neural network optimization, we determine the statistical significance for a hypothetical discovery at future LHC runs. In particular, we show that we can not safely exclude VLLs for masses greater than 200 GeV. For VLQ’s in our model, we show that we can probe their masses up to 3.8 TeV, if we take only into account the high-luminosity phase of the LHC. Considering Run-III luminosities, we can also exclude VLQs for masses up to 3.4 TeV. We also show how the model with predicted VLL masses accommodates the muon anomalous magnetic moment.

An extended 3-3-1 model with two scalar triplets and linear seesaw mechanism

Low energy linear seesaw mechanism responsible for the generation of the tiny active neutrino masses, is implemented in the extended 3-3-1 model with two scalar triplets and right handed Majorana neutrinos where the gauge symmetry is supplemented by the $A_4$ flavor discrete group and other auxiliary cyclic symmetries, whose spontaneous breaking produces the observed pattern of SM charged fermion masses and fermionic mixing parameters. Our model is consistent with the low energy SM fermion flavor data as well as with the constraints arising from meson oscillations. Some phenomenological aspects such as the $Z^\prime$ production at proton proton collider and the lepton flavor violating decay of the SM-like Higgs boson are discussed. The scalar potential of the model is analyzed in detail and the SM-like Higgs boson is identified.

CP odd weak basis invariants in minimal see-saw model and leptogenesis

Abstract In this paper, we derive the relationship between the weak basis invariants (WB) related to CP violation responsible for leptogenesis and CP violation relevant at low energy. We examine all the experimentally viable cases of Frampton-Glashow and Yanagida (FGY) model, in order to construct the WB invariants in terms of left handed Majorana neutrino mass matrix elements, and thus finding the necessary and sufficient condition for CP conservation. Further for all the viable FGY texture zeros, we have shown the explicit dependence of WB invariants on Dirac type and Majorana type CP violating phases. In the end, we discuss the implication of such interrelationships on leptogenesis.

A simple extension of the SM that can explain the ()μ anomaly, small neutrino mass and a dark matter

In this work we propose a simple extension of the Standard Model (SM) by adding to it eleven new particles. Three heavy lepton (fe, fμ, fτ), singlets under carrying respective lepton numbers, charged under with Y = −2 and transforming under a discrete symmetry as . One scalar (ϕ2), a singlet under all the SM gauge groups and transforms under the discrete symmetry as which does not develop a non zero vacuum-expectation-value (VEV). One more scalar (ϕ3), a singlet under all the SM gauge groups and invariant under discrete symmetry which develops a non zero VEV (v3) and gives masses to fis, ϕ2 and neutrinos. Three right handed neutrinos () and three left handed Majorana neutrinos (siL). With these new additional particles added to the SM we have been able to give explanations to the long standing muon (g-2) anomaly as well as the smallness of neutrino masses by the inverse seesaw mechanism. Also in this model we have a very suitable scalar dark matter (DM) candidate in ϕ2 with allows a mass as high as 53 GeV, although due to a large Yukawa coupling required to explain the muon (g-2), its contribution to the DM relic density turn out to be too small and so it can account only for a small fraction of the DM relic density of the Universe.

A highly predictive A4 flavor 3-3-1 model with radiative inverse seesaw mechanism

We build a highly predictive 3-3-1 model, where the field content is extended by including several SU(3)L scalar singlets and six right handed Majorana neutrinos. In our model the gauge symmetry is supplemented by the discrete group, which allows to get a very good description of the low energy fermion flavor data. In the model under consideration, the discrete group is broken at very high energy scale down to the preserved Z2 discrete symmetry, thus generating the observed pattern of SM fermion masses and mixing angles and allowing the implementation of the loop level inverse seesaw mechanism for the generation of the light active neutrino masses, respectively. The obtained values for the physical observables in the quark sector agree with the experimental data, whereas those ones for the lepton sector also do, only for the case of inverted neutrino mass spectrum. The normal neutrino mass hierarchy scenario of the model is ruled out by the neutrino oscillation experimental data. We find an effective Majorana neutrino mass parameter of neutrinoless double beta decay of mee = 46.9 meV, a leptonic Dirac CP violating phase of −81.37° and a Jarlskog invariant of about 10−2 for the inverted neutrino mass hierarchy. The preserved Z2 symmetry allows for a stable scalar dark matter candidate.

Constraining the right-handed gauge boson mass from lepton number violating meson decays in a low scale left-right model

We analyze the lepton number violating (LNV) meson decays that arise in a TeV scale Left Right Symmetry model. The right handed Majorana neutrino $N$ along with the right handed or Standard Model gauge bosons mediate the meson decays and provide a resonant enhancement of the rates if the mass of $N$ ($M_N$) lies in the range $\sim (100\, \rm{MeV}-5\, \rm{GeV})$. Using the expected upper limits on the number of events for the LNV decay modes $M_{1}^{+} \to\ell^{+}\ell^{+}\pi^{-}$~($M_{1}=B, D, D_{s}, K$), we derive constraints plausible on the mass of the right handed charged gauge boson by future searches at the ongoing NA62 and LHCb experiments at CERN, the upcoming Belle II at SuperKEK, as well as at the proposed future experiments, SHiP and FCC-ee. These bounds are complimentary to the limits from same-sign dilepton search at Large Hadron Collider (LHC). The very high intensity of Charmed mesons expected to be produced at SHiP will result in a far more stringent bound, $M_{W_R}>18.4$~TeV (corresponding to $M_N=1.46$~GeV), than the other existing bounds from collider and neutrinoless double beta decay searches.

Higgs boson masses in the MSSM with heavy Majorana neutrinos

We present a full diagrammatic computation of the one-loop corrections from the neutrino/sneutrino sector to the renormalized neutral CP-even Higgs boson self-energies and the lightest Higgs boson mass, Mh, within the context of the so-called MSSM-seesaw scenario. This consists of the Minimal Supersymmetric Standard Model with the addition of massive right handed Majorana neutrinos and their supersymmetric partners, and where the seesaw mechanism is used for the lightest neutrino mass generation. We explore the dependence on all the parameters involved, with particular emphasis in the role played by the heavy Majorana scale. We restrict ourselves to the case of one generation of neutrinos/sneutrinos. For the numerical part of the study, we consider a very wide range of values for all the parameters involved. We find sizeable corrections to Mh, which are negative in the region where the Majorana scale is large (10^{13}-10^{15} GeV) and the lightest neutrino mass is within a range inspired by data (0.1-1 eV). For some regions of the MSSM-seesaw parameter space, the corrections to Mh are substantially larger than the anticipated Large Hadron Collider precision.

Sneutrino condensate as a candidate for the hot big bang cosmology

If inflationary paradigm is correct, then it must create conditions for the hot big bang model with all observed matter, baryons and the seed perturbations for the structure formation. In this paper we propose a scenario where the inflaton energy density is dumped into the bulk in a brane world setup, and all the required physical conditions are created by the right handed neutrino sector within supersymmetry. The scalar component of the right handed Majorana neutrino is responsible for generating the scale invariant fluctuations in the cosmic microwave background radiation, reheating the Universe at a temperature~$T_{rh}\leq 10^{9}$ GeV, and finally generating the lepton/baryon asymmetry, $n_{B}/s\sim 10^{-10}$, with no lepton/baryon isocurvature fluctuations.

Non-Abelian soft boson phase transitions and large-scale structure.

A new class of models with Pseudo-Nambu-Goldstone bosons (PNGB`s) is constructed using a non-Abelian symmetry in the right handed Majorana neutrino sector of see-saw neutrino mass models. The phase structure of these models is examined both at zero and non-zero temperatures, with particular emphasis on their phase transition characteristics. We find that the vacuum manifold of these models exhibits a rich structure in terms of possible topological defects, and we argue that these models may have applications to late time phase transition theories of structure formation.