scholarly journals Renormalizable SO(10) GUT with Suppressed Dimension-5 Proton Decays

2020 ◽  
Author(s):  
Naoyuki Haba ◽  
Yukihiro Mimura ◽  
Toshifumi Yamada
Keyword(s):  
Neutrino Mass ◽  
Mass Matrix ◽  
Susy Breaking ◽  
Seesaw Mechanism ◽  
Yukawa Couplings ◽  
Active Neutrino ◽  
Experimental Bound ◽  
Pmns Matrix ◽  
Breaking Scale

Abstract We study a renormalizable SUSY SO(10) GUT model where the Yukawa couplings of single 10, single $${\bf \overline{126}}$$ and single 120 fields, Y10, Y126, Y120, account for the quark and lepton Yukawa couplings and the neutrino mass. We pursue the possibility that Y10, Y126, Y120 reproduce the correct quark and lepton masses, CKM and PMNS matrices and neutrino mass differences, and at the same time suppress dimension-5 proton decays (proton decays via colored Higgsino exchange) through their texture, so that the soft SUSY breaking scale can be reduced as much as possible without conflicting the current experimental bound on proton decays. We perform a numerical search for such a texture, and investigate implications of that texture on unknown neutrino parameters, the Dirac CP phase of PMNS matrix, the lightest neutrino mass and the (1, 1)-component of the neutrino mass matrix in the charged lepton basis. Here we concentrate on the case when the active neutrino mass is generated mostly by the Type-2 seesaw mechanism, in which case we can obtain predictions for the neutrino parameters from the condition that dimension-5 proton decays be suppressed as much as possible.

scholarly journals TRIBIMAXIMAL MIXING IN NEUTRINO MASS MATRICES WITH TEXTURE ZEROS OR VANISHING MINORS

2011 ◽  
Vol 26 (07) ◽  
pp. 501-514 ◽  
Author(s):  
S. DEV ◽  
SHIVANI GUPTA ◽  
RADHA RAMAN GAUTAM
Keyword(s):  
Neutrino Mass ◽  
Mass Matrix ◽  
Mass Scale ◽  
Neutrino Mass Matrix ◽  
Seesaw Mechanism ◽  
Majorana Mass ◽  
Absolute Mass ◽  
Mass Matrices ◽  
The One ◽  
The Right

We study the existence of one/two texture zeros or one/two vanishing minors in the neutrino mass matrix with μτ symmetry. In the basis where the charged lepton mass matrix and the Dirac neutrino mass matrix are diagonal, the one/two zeros or one/two vanishing minors on the right-handed Majorana mass matrix having μτ symmetry will propagate via seesaw mechanism as one/two vanishing minors or one/two texture zeros in the neutrino mass matrix with μτ symmetry respectively. It is found that only five such texture structures of the neutrino mass matrix are phenomenologically viable. For tribimaximal mixing, these texture structures reduce the number of free parameters to one. Interesting predictions are obtained for the effective Majorana mass Mee, the absolute mass scale and the Majorana-type CP violating phases.

scholarly journals Seesaw mechanism and structure of neutrino mass matrix

2000 ◽  
Vol 478 (1-3) ◽  
pp. 215-223 ◽  
Author(s):  
E.Kh. Akhmedov ◽  
G.C. Branco ◽  
M.N. Rebelo
Keyword(s):  
Neutrino Mass ◽  
Mass Matrix ◽  
Neutrino Mass Matrix ◽  
Seesaw Mechanism

scholarly journals Type II seesaw origin of nonzero θ13, δCP and leptogenesis

2014 ◽  
Vol 29 (22) ◽  
pp. 1450108 ◽  
Author(s):  
Debasish Borah
Keyword(s):  
Neutrino Mass ◽  
Mass Matrix ◽  
Neutrino Mass Matrix ◽  
Type I ◽  
Type Ii ◽  
Mixing Angle ◽  
Yukawa Couplings ◽  
Minimal Structure ◽  
Reactor Mixing ◽  
The Universe

We discuss the possible origin of nonzero reactor mixing angle θ13 and Dirac CP phase δ CP in the leptonic sector from a combination of type I and type II seesaw mechanisms. Type I seesaw contribution to neutrino mass matrix is of tri-bimaximal (TBM) type which gives rise to vanishing θ13 leaving the Dirac CP phase undetermined. If the Dirac neutrino mass matrix is assumed to take the diagonal charged lepton (CL) type structure, such a TBM type neutrino mass matrix originating from type I seesaw corresponds to real values of Dirac Yukawa couplings in the terms [Formula: see text]. This makes the process of right-handed heavy neutrino decay into a light neutrino and Higgs (N → νH) CP preserving ruling out the possibility of leptogenesis. Here we consider the type II seesaw term as the common origin of nonzero θ13 and δ CP by taking it as a perturbation to the leading order TBM type neutrino mass matrix. First, we numerically fit the type I seesaw term by taking oscillation as well as cosmology data and then compute the predictions for neutrino parameters after the type II seesaw term is introduced. We consider a minimal structure of the type II seesaw term and check whether the predictions for neutrino parameters lie in the 3σ range. We also compute the predictions for baryon asymmetry of the universe by considering type II seesaw term as the only source of CP violation and compare it with the latest cosmology data.

scholarly journals PERTURBED INVARIANT UNDER A CYCLIC PERMUTATION WITH TRACE OF NEUTRINO MASS MATRIX REMAIN CONSTANT

2011 ◽  
Vol 26 (08) ◽  
pp. 567-574 ◽  
Author(s):  
ASAN DAMANIK
Keyword(s):  
Neutrino Mass ◽  
Mass Matrix ◽  
Cyclic Permutation ◽  
Neutrino Mass Matrix ◽  
Neutrino Masses ◽  
Inverted Hierarchy ◽  
Seesaw Mechanism ◽  
Mixing Parameters ◽  
Difference Formula ◽  
Mass Matrices

We construct a neutrino mass matrix Mν via a seesaw mechanism with perturbed invariant under a cyclic permutation by introducing a parameter δ into the diagonal elements of Mν with the assumption that trace of the perturbed Mν is equal to trace of the unperturbed Mν. We found that the perturbed neutrino mass matrices Mν can predict the mass-squared difference [Formula: see text] with the possible hierarchy of neutrino mass is normal or inverted hierarchy. By using the advantages of the mass-squared differences and mixing parameters data from neutrino oscillation experiments, we then have neutrino masses in inverted hierarchy with masses: |m1| = 0.101023 eV , |m2| = 0.101428 eV and |m3| = 0.084413 eV .

WHY IS TOP HEAVIER THAN BOTTOM? YUKAWA AND MASS UNIFICATION IN SUSY MODEL

1992 ◽  
Vol 07 (36) ◽  
pp. 3379-3390 ◽  
Author(s):  
MASAKO BANDO ◽  
TAICHIRO KUGO ◽  
NOBUHIRO MAEKAWA ◽  
HIROAKI NAKANO
Keyword(s):  
Lower Bound ◽  
Top Quark ◽  
Susy Breaking ◽  
Third Generation ◽  
Parameter Choice ◽  
Yukawa Couplings ◽  
The Third ◽  
Mass Pattern ◽  
Gauge Interaction ◽  
Breaking Scale

We examine whether the unification constraints on the Yukawa couplings and on the Higgs masses in the minimal supersymmetric Standard Model can be consistent with the observed mass pattern of the third generation fermions. The effects of the QCD interaction and the SU(2)R breaking owing to the U(1) Y gauge interaction and the absence of ντR are crucial. We observe that the parameter choice of “no-scale” supergravity is favored and the SUSY breaking scale has a lower bound, in order for the top quark to be much heavier than the bottom quark.

scholarly journals Neutrino masses in an $$SU(4)\otimes U(1)$$-electroweak model with a scalar decuplet

2019 ◽  
Vol 79 (10) ◽  
Author(s):  
N. Anh Ky ◽  
N. T. Hong Van ◽  
D. Nguyen Dinh ◽  
P. Quang Van
Keyword(s):  
Symmetry Breaking ◽  
Neutrino Mass ◽  
Particle Physics ◽  
Mass Matrix ◽  
Neutrino Masses ◽  
Coupling Coefficients ◽  
Mass Model ◽  
Yukawa Couplings ◽  
Distribution Shape ◽  
Independent Distribution

Abstract A neutrino mass model is suggested within an $$SU(4)\otimes U(1)$$SU(4)⊗U(1)-electroweak theory. The smallness of neutrino masses can be guaranteed by a seesaw mechanism realized through Yukawa couplings to a scalar SU(4)-decuplet. In this scheme the light active neutrinos are accompanied by heavy neutrinos, which may have masses at different scales, including those within eV–MeV scales investigated quite intensively in both particle physics and astrophysics/cosmology. The flavour neutrinos are superpositions of light neutrinos and a small fraction of heavy neutrinos with the mixing to be determined by the model’s parameters (Yukawa coupling coefficients or symmetry breaking scales). The distribution shape of the Yukawa couplings can be visualized via a model-independent distribution of the neutrino mass matrix elements derived by using the current experimental data. The absolute values of these Yukawa couplings are able to be determined if the symmetry breaking scales are known, and vice versa. With reference to several current and near future experiments, detectable bounds of these heavy neutrinos at different mass scales are discussed and estimated.

scholarly journals Effects of the Variation of SUSY Breaking Scale on Yukawa and Gauge Couplings Unification

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Konsam Sashikanta Singh ◽  
N. Nimai Singh
Keyword(s):  
Gauge Coupling ◽  
Proton Decay ◽  
Susy Breaking ◽  
Threshold Effects ◽  
Third Generation ◽  
Heavy Particles ◽  
Yukawa Couplings ◽  
Decay Lifetime ◽  
Single Scale ◽  
Breaking Scale

The present analysis addresses an interesting primary question on how do the gauge and Yukawa couplings unification scales vary with varying SUSY breaking scalesms, assuming a single scale for all supersymmetric particles. It is observed that the gauge coupling unification scale increases withmswhereas third-generation Yukawa couplings unification scale decreases withms. The rising of the unification scale and also the mass of the color triplet multiplets is necessary to increase the proton decay lifetime; the analysis is carried out with two-loop RGEs for the gauge and Yukawa couplings within the minimal supersymmetric SU(5) model, while ignoring for simplicity the threshold effects of the heavy particles, which could be as large as a few percentages.

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