scholarly journals The Grimus–Neufeld Model with FlexibleSUSY at One-Loop

Symmetry ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 1418
Author(s):  
Simonas Draukšas ◽  
Vytautas Dūdėnas ◽  
Thomas Gajdosik ◽  
Andrius Juodagalvis ◽  
Paulius Juodsnukis ◽  
...  

The Grimus–Neufeld model can explain the smallness of measured neutrino masses by extending the Standard Model with a single heavy neutrino and a second Higgs doublet, using the seesaw mechanism and radiative mass generation. The Grimus–Lavoura approximation allows us to calculate the light neutrino masses analytically. By inverting these analytic expressions, we determine the neutrino Yukawa couplings from the measured neutrino mass differences and the neutrino mixing matrix. Short-cutting the full renormalization of the model, we implement the Grimus–Neufeld model in the spectrum calculator FlexibleSUSY and check the consistency of the implementation. These checks hint that FlexibleSUSY is able to do the job of numerical renormalization in a restricted parameter space. As a summary, we also comment on further steps of the implementation and the use of FlexibleSUSY for the model.

2020 ◽  
Vol 2020 (8) ◽  
Author(s):  
Shilpa Jangid ◽  
Priyotosh Bandyopadhyay ◽  
P.S. Bhupal Dev ◽  
Arjun Kumar

Abstract We analyze the vacuum stability in the inert Higgs doublet extension of the Standard Model (SM), augmented by right-handed neutrinos (RHNs) to explain neutrino masses at tree level by the seesaw mechanism. We make a comparative study of the high- and low-scale seesaw scenarios and the effect of the Dirac neutrino Yukawa couplings on the stability of the Higgs potential. Bounds on the scalar quartic couplings and Dirac Yukawa couplings are obtained from vacuum stability and perturbativity considerations. These bounds are found to be relevant only for low-scale seesaw scenarios with relatively large Yukawa couplings. The regions corresponding to stability, metastability and instability of the electroweak vacuum are identified. These theoretical constraints give a very predictive parameter space for the couplings and masses of the new scalars and RHNs which can be tested at the LHC and future colliders. The lightest non-SM neutral CP-even/odd scalar can be a good dark matter candidate and the corresponding collider signatures are also predicted for the model.


2010 ◽  
Vol 25 (23) ◽  
pp. 4325-4337 ◽  
Author(s):  
S. T. PETCOV

The phenomenology of 3-neutrino mixing and of the related Dirac and Majorana leptonic CP violation is reviewed. The leptogenesis scenario of generation of the baryon asymmetry of the Universe, which is based on the see-saw mechanism of neutrino mass generation, is considered. The results showing that the CP violation necessary for the generation of the baryon asymmetry of the Universe in leptogenesis can be due exclusively to the Dirac and/or Majorana CP-violating phase(s) in the neutrino mixing matrix U are briefly reviewed.


2020 ◽  
Vol 35 (21) ◽  
pp. 2050117
Author(s):  
Heng-Yu Chen ◽  
Ilia Gogoladze ◽  
Shan Hu ◽  
Tianjun Li ◽  
Lina Wu

We present a class of nonsupersymmetric models in which the so-called critical Higgs inflation [Formula: see text] can be naturally realized without using specific values for Higgs and top quark masses. In these scenarios, the Standard Model (SM) vacuum stability problem, gauge coupling unification, neutrino mass generation and Higgs inflation mechanism are linked to each other. We adopt in our models Type I seesaw mechanism for neutrino masses. An appropriate choice of the Type I seesaw scale allows us to have an arbitrarily small but positive value of SM Higgs quartic coupling around the inflation scale. We present a few benchmark points where we show that the scalar spectral indices are around 0.9626 and 0.9685 for the number of [Formula: see text]-folding [Formula: see text] and [Formula: see text], respectively. The tensor-to-scalar ratios are of the order of [Formula: see text]. The running of the scalar spectral index is negative and is of the order of [Formula: see text].


2002 ◽  
Vol 17 (13) ◽  
pp. 771-778 ◽  
Author(s):  
SALAH NASRI ◽  
SHERIF MOUSSA

We propose a model for neutrino mass generation in which no physics beyond a TeV is required. We extend the standard model by adding two charged singlet fields with lepton number two. Dirac neutrino masses mνD ≤ MeV are generated at the one-loop level. Small left-handed Majorana neutrino masses can be generated via the seesaw mechanism with right-handed neutrino masses MR of order TeV scale.


2014 ◽  
Vol 2014 ◽  
pp. 1-24 ◽  
Author(s):  
V. V. Vien ◽  
H. N. Long

A newS4flavor model based onSU(3)C⊗SU(3)L⊗U(1)Xgauge symmetry responsible for fermion masses and mixings is constructed. The neutrinos get small masses from only an antisextet ofSU(3)Lwhich is in a doublet underS4. In this work, we assume the VEVs of the antisextet differ from each other underS4and the difference of these VEVs is regarded as a small perturbation, and then the model can fit the experimental data on neutrino masses and mixings. Our results show that the neutrino masses are naturally small and a deviation from the tribimaximal neutrino mixing form can be realized. The quark masses and mixing matrix are also discussed. The number of required Higgs multiplets is less and the scalar potential of the model is simpler than those of the model based onS3and our previousS4model. The assignation of VEVs to antisextet leads to the mixing of the new gauge bosons and those in the standard model. The mixing in the charged gauge bosons as well as the neutral gauge bosons is considered.


2013 ◽  
Vol 28 (32) ◽  
pp. 1350159 ◽  
Author(s):  
V. V. VIEN ◽  
H. N. LONG

We construct a D4flavor model based on SU(3)C⊗SU(3)L⊗U(1)Xgauge symmetry responsible for fermion masses and mixings. The neutrinos get small masses from antisextets which are in a singlet and a doublet under D4. If the D4symmetry is violated as perturbation by a Higgs triplet under SU(3)Land lying in [Formula: see text] of D4, the corresponding neutrino mass mixing matrix gets the most general form. In this case, the model can fit the experimental data in 2012 on neutrino masses and mixing. Our results show that the neutrino masses are naturally small and a little deviation from the tribimaximal neutrino mixing form can be realized. The quark masses and mixing matrix are also discussed. In the model under consideration, the CKM matrix can be different from the unit matrix. The scalar potential of the model is more simpler than those of the model based on S3and S4. Assignation of VEVs to antisextets leads to the mixing of the new gauge bosons and those in the Standard Model. The mixing in the charged gauge bosons as well as the neutral gauge boson is considered.


2009 ◽  
Vol 24 (27) ◽  
pp. 2161-2165 ◽  
Author(s):  
ERNEST MA

If neutrino masses are obtained via the canonical seesaw mechanism, based on an underlying 2 ×2 mass matrix, unitarity violation of the neutrino mixing matrix is unavoidable, but its effect is extremely small. On the other hand, in the inverse (and linear) seesaw mechanisms, based on an underlying 3 ×3 mass matrix, it can be significant and possibly observable. This 3 ×3 matrix is examined in more detail, and a new variation (the lopsided seesaw) is proposed which has features of both mechanisms. A concrete example based on U (1)N is discussed.


2020 ◽  
Vol 2020 (12) ◽  
Author(s):  
Sebastian A. R. Ellis ◽  
Kevin J. Kelly ◽  
Shirley Weishi Li

Abstract The unitarity of the lepton mixing matrix is a critical assumption underlying the standard neutrino-mixing paradigm. However, many models seeking to explain the as-yet-unknown origin of neutrino masses predict deviations from unitarity in the mixing of the active neutrino states. Motivated by the prospect that future experiments may provide a precise measurement of the lepton mixing matrix, we revisit current constraints on unitarity violation from oscillation measurements and project how next-generation experiments will improve our current knowledge. With the next-generation data, the normalizations of all rows and columns of the lepton mixing matrix will be constrained to ≲10% precision, with the e-row best measured at ≲1% and the τ-row worst measured at ∼10% precision. The measurements of the mixing matrix elements themselves will be improved on average by a factor of 3. We highlight the complementarity of DUNE, T2HK, JUNO, and IceCube Upgrade for these improvements, as well as the importance of ντ appearance measurements and sterile neutrino searches for tests of leptonic unitarity.


2021 ◽  
Vol 2021 (3) ◽  
Author(s):  
Sanjoy Mandal ◽  
Rahul Srivastava ◽  
José W. F. Valle

Abstract We investigate the stability of Higgs potential in inverse seesaw models. We derive the full two-loop RGEs of the relevant parameters, such as the quartic Higgs self-coupling, taking thresholds into account. We find that for relatively large Yukawa couplings the Higgs quartic self-coupling goes negative well below the Standard Model instability scale ∼ 1010 GeV. We show, however, that the “dynamical” inverse seesaw with spontaneous lepton number violation can lead to a completely consistent and stable Higgs vacuum up to the Planck scale.


2014 ◽  
Vol 92 (12) ◽  
pp. 1501-1527 ◽  
Author(s):  
Carlos Castro

A Clifford Cl(5, C) unified gauge field theory formulation of conformal gravity and U(4) × U(4) × U(4) Yang–Mills in 4D, is reviewed along with its implications for the Pati–Salam (PS) group SU(4) × SU(2)L × SU(2)R, and trinification grand unified theory models of three fermion generations based on the group SU(3)C × SU(3)L × SU(3)R. We proceed with a brief review of a unification program of 4D gravity and SU(3) × SU(2) × U(1) Yang–Mills emerging from 8D pure quaternionic gravity. A realization of E8 in terms of the Cl(16) = Cl(8) ⊗ Cl(8) generators follows, as a preamble to F. Smith’s E8 and Cl(16) = Cl(8) ⊗ Cl(8) unification model in 8D. The study of chiral fermions and instanton backgrounds in CP2 and CP3 related to the problem of obtaining three fermion generations is thoroughly studied. We continue with the evaluation of the coupling constants and particle masses based on the geometry of bounded complex homogeneous domains and geometric probability theory. An analysis of neutrino masses, Cabbibo–Kobayashi–Maskawa quark-mixing matrix parameters, and neutrino-mixing matrix parameters follows. We finalize with some concluding remarks about other proposals for the unification of gravity and the Standard Model, like string, M, and F theories and noncommutative and nonassociative geometry.


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