scholarly journals Loop suppressed light fermion masses with U(1)R gauge symmetry

2017 ◽  
Vol 96 (1) ◽  
Author(s):  
Takaaki Nomura ◽  
Hiroshi Okada
2008 ◽  
Vol 23 (14) ◽  
pp. 1011-1030 ◽  
Author(s):  
ION I. COTĂESCU ◽  
ADRIAN PALCU

The Pisano–Pleitez–Frampton 3-3-1 model is revisited here within the framework of the general method for solving gauge models with high symmetries. This exact algebraical approach — proposed several years ago by one of us — was designed to include a minimal Higgs mechanism that spontaneously breaks the gauge symmetry up to the universal U(1)em electromagnetic one and, consequently, to supply the mass spectrum and the couplings of the currents for all the particles in the model. We prove in this paper that this powerful tool, when is applied to the PPF 3-3-1 model, naturally recovers the whole Standard Model phenomenology and, in addition, predicts — since a proper parametrization is employed — viable results such as: (i) the exact expressions for the boson and fermion masses, (ii) the couplings of the charged and neutral currents and (iii) a plausible neutrino mass pattern. A generalized Weinberg transformation is implemented, while the mixing between the neutral bosons Z and Z′ is performed as a necessary step by the method itself. Some phenomenological consequences are also sketched, including the strange possibility that simultaneously m(Z) = m(Z′) and m(W) = m(V) hold.


2012 ◽  
Vol 27 (01) ◽  
pp. 1250005 ◽  
Author(s):  
ABDELHAMID ALBAID

Flavor violating processes in the quark and lepton sectors are investigated within a realistic supersymmetric SO(10)×A4 grand unification model. By employing exotic heavy fermion fields, this model successfully describes various features of the fermion masses and mixings including large neutrino mixings accompanied by small quark mixings. In this model the flavor violation is induced at GUT scale, at which A4 flavor symmetry is broken, as a consequence of the large mixings of the light fermion fields with these exotic heavy fields. The stringent experimental constraint from μ→eγ decay rate necessitates a high degree of degeneracy of the supersymmetry breaking soft scalar masses of the exotic heavy fields and supersymmetric scalar partners of the light fermion fields. The choice of slepton masses of order 1 TeV is found to be consistent with the constraints from branching ratio of μ→eγ and with all other flavor changing neutral current processes being sufficiently suppressed.


1989 ◽  
Vol 04 (12) ◽  
pp. 1159-1167
Author(s):  
A. DAVIDSON ◽  
B. MARGOLIS ◽  
J. ROBINSON ◽  
P. VALIN

We consider the hypothesis that (i) mv≃0 because the neutrino is SU (3)c× U (1) e.m. neutral, (ii) m electron = 0 at the isospin limit where mu=md, and (iii) all first-generation fer-mions turn massless as αc, α e.m. →0. This hypothesis is supported by the empirical Abraham-Lorentz-type mass formula m=(ζ1Q+ζ2B)2, whose quadratic structure is attributed to a universal seesaw mechanism. We demonstrate how such a formula can stay exact even when switching on the inter-generational mixings. We present a complete model with the above features which gives quark and lepton masses and the K-M matrix, including CP violation.


2016 ◽  
Vol 760 ◽  
pp. 59-62 ◽  
Author(s):  
Corey Kownacki ◽  
Ernest Ma
Keyword(s):  

2017 ◽  
Vol 32 (16) ◽  
pp. 1750093 ◽  
Author(s):  
J. C. Montero ◽  
V. Pleitez ◽  
B. L. Sánchez-Vega ◽  
M. C. Rodriguez

We build a supersymmetric version with [Formula: see text] gauge symmetry, where [Formula: see text] is a new charge and [Formula: see text] and [Formula: see text] are the usual baryonic and leptonic numbers. The model has three right-handed neutrinos with identical [Formula: see text] charges, and can accommodate all fermion masses at the tree level. In particular, the type I seesaw mechanism is implemented for the generation of the active neutrino masses. We obtain the mass spectra of all sectors and for the scalar one we also give the flat directions allowed by the model.


2014 ◽  
Vol 29 (23) ◽  
pp. 1450122 ◽  
Author(s):  
V. V. Vien

We propose a new D4flavor model based on SU (3)C⊗ SU (3)L⊗ U (1)Xgauge symmetry responsible for fermion masses and mixings in which all fermion fields act only as singlets under D4which differs from our previous work. The neutrinos get small masses from two SU (3)Lanti-sextets and one SU (3)Ltriplet which are all in singlets under D4. If a SU (3)LHiggs triplet, lying in [Formula: see text] under D4, is considered as a perturbation the corresponding neutrino mass mixing matrix gets the most general form. In this case, the model can fit the most recent data on neutrino masses and mixing with nonzero θ13. Our results show that the neutrino masses are naturally small. The sum of three light neutrino masses and the effective mass governing neutrinoless double beta decay are obtained that are consistent with the recent data.


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