scholarly journals Fermion mass hierarchies from supersymmetric gauged flavour symmetry in 5D

2021 ◽  
Vol 10 (6) ◽  
Author(s):  
Ketan Patel
Keyword(s):  
Vacuum Expectation ◽  
Vacuum Expectation Value ◽  
Fermion Mass ◽  
Order Unity ◽  
Anomaly Cancellation ◽  
Fundamental Parameters ◽  
Yukawa Couplings ◽  
Fifth Dimension ◽  
Fermion Masses ◽  
The Masses

A mechanism to generate realistic fermion mass hierarchies based on supersymmetric gauged U(1)_FU(1)F symmetry in flat five-dimensional (5D) spacetime is proposed. The fifth dimension is compactified on S^1/Z_2S1/Z2 orbifold. The standard model fermions charged under the extra abelian symmetry along with their superpartners live in the 5D bulk. Bulk masses of fermions are generated by the vacuum expectation value of N=2N=2 superpartner of U(1)_FU(1)F gauge field, and they are proportional to U(1)_FU(1)F charges of respective fermions. This decides localization of fermions in the extra dimension, which in turn gives rise to exponentially suppressed Yukawa couplings in the effective 4D theory. Anomaly cancellation puts stringent constraints on the allowed U(1)_FU(1)F charges which leads to correlations between the masses of quarks and leptons. We perform an extensive numerical scan and obtain several solutions for anomaly-free U(1)_FU(1)F, which describe the observed pattern of fermion masses and mixing with all the fundamental parameters of order unity. It is found that the possible existence of SM singlet neutrinos substantially improves the spectrum of solutions by offering more freedom in choosing U(1)_FU(1)F charges. The model predicts Z^\primeZ′ boson mediating flavour violating interactions in both the quark and lepton sectors with the couplings which can be explicitly determined from the Yukawa couplings.

scholarly journals Improving fermion mass hierarchy in grand gauge–Higgs unification with localized gauge kinetic terms

2020 ◽  
Vol 80 (10) ◽  
Author(s):  
Nobuhito Maru ◽  
Yoshiki Yatagai
Keyword(s):  
Higgs Boson ◽  
Top Quark ◽  
Gauge Coupling ◽  
Vacuum Expectation ◽  
Vacuum Expectation Value ◽  
Boson Mass ◽  
Fermion Mass ◽  
Mass Hierarchy ◽  
Higgs Boson Mass ◽  
Fermion Masses

AbstractGrand gauge–Higgs unification of five dimensional SU(6) gauge theory on an orbifold $$S^1/Z_2$$ S 1 / Z 2 with localized gauge kinetic terms is discussed. The Standard model (SM) fermions on one of the boundaries and some massive bulk fermions coupling to the SM fermions on the boundary are introduced, so that they respect an SU(5) symmetry structure. The SM fermion masses including top quark are reproduced by mild tuning the bulk masses and parameters of the localized gauge kinetic terms. Gauge coupling universality is not guaranteed by the presence of the localized gauge kinetic terms and it severely constrains the Higgs vacuum expectation value. Higgs potential analysis shows that the electroweak symmetry breaking occurs by introducing additional bulk fermions in simplified representations. The localized gauge kinetic terms enhance the magnitude of the compactification scale, which helps Higgs boson mass large. Indeed the observed Higgs boson mass 125 GeV is obtained.

scholarly journals DYNAMICAL FERMION MASSES UNDER THE INFLUENCE OF KALUZA–KLEIN FERMIONS AND A BULK ABELIAN GAUGE FIELD

2010 ◽  
Vol 25 (35) ◽  
pp. 2933-2945 ◽  
Author(s):  
D. EBERT ◽  
V. CH. ZHUKOVSKY ◽  
A. V. TYUKOV
Keyword(s):  
Gauge Field ◽  
Effective Potential ◽  
Dynamical Variable ◽  
Fermion Mass ◽  
Coupling Constant ◽  
Mass Generation ◽  
Abelian Gauge ◽  
Fifth Dimension ◽  
Fermion Masses ◽  
The Masses

The dynamical fermion mass generation on the 3-brane in the 5D spacetime is discussed in a model with bulk fermions in interaction with fermions on the branes assuming the presence of a constant Abelian gauge field A5 in the bulk. We calculate the effective potential as a function of the fermion masses and the gauge field A5. The masses can be found from the stationarity condition for the effective potential (the gap equation). We formulate the equation for the mass spectrum of the 4D-fermions. The phases with finite and vanishing fermion masses are studied and the dependence of the masses on the radius of the fifth dimension is analyzed. The influence of the A5-gauge field on the symmetry breaking is considered both when this field is a background parameter and a dynamical variable. The critical values of the A5 field, the coupling constant and the radius are examined.

scholarly journals FLAVOR SYMMETRY AND VACUUM ALIGNED MASS TEXTURES

2007 ◽  
Vol 16 (05) ◽  
pp. 1427-1436 ◽  
Author(s):  
SATORU KANEKO ◽  
HIDEYUKI SAWANAKA ◽  
TAKAYA SHINGAI ◽  
MORIMITSU TANIMOTO ◽  
KOICHI YOSHIOKA
Keyword(s):  
Scalar Potential ◽  
Vacuum Expectation ◽  
Vacuum Expectation Value ◽  
Flavor Symmetry ◽  
Yukawa Couplings ◽  
Flavor Changing ◽  
Symmetry Approach ◽  
Mass Matrices ◽  
Vanishing Elements ◽  
Higgs Fields

A texture-zeros is an approach to reduce the number of free parameters in Yukawa couplings and it is one of the most attractive ones. In our paper, we discuss the origin of zero-structure in texture-zeros by S3 flavor symmetry approach. Some of electroweak doublet Higgs fields have vanishing vacuum expectation value (VEV) which leads to vanishing elements in quark and lepton mass matrices. Then, the structure of supersymmetric scalar potential is analyzed and Higgs fields have non-trivial S3 charges. As a prediction of our paper, a lower bound of a MNS matrix element, Ue3 ≥ 0.04, is obtained. The suppression of flavor-changing neutral currents (FCNC) mediated by the Higgs fields is discussed and lower bounds of the Higgs masses are derived.

scholarly journals Leptogenesis and fermion mass fit in a renormalizable SO(10) model

2021 ◽  
Vol 2021 (12) ◽  
Author(s):  
V. Suryanarayana Mummidi ◽  
Ketan M. Patel
Keyword(s):  
Numerical Solutions ◽  
Double Beta Decay ◽  
Fermion Mass ◽  
Strong Correlations ◽  
Yukawa Couplings ◽  
Mixing Parameters ◽  
Fermion Masses ◽  
The Standard Model ◽  
The Right ◽  
Yukawa Sector

Abstract A non-supersymmetric renormalizable SO(10) model is investigated for its viability in explaining the observed fermion masses and mixing parameters along with the baryon asymmetry produced via thermal leptogenesis. The Yukawa sector of the model consists of complex 10H and $$ {\overline{126}}_H $$ 126 ¯ H scalars with a Peccei-Quinn like symmetry and it leads to strong correlations among the Yukawa couplings of all the standard model fermions including the couplings and masses of the right-handed (RH) neutrinos. The latter implies the necessity to include the second lightest RH neutrino and flavor effects for the precision computation of leptogenesis. We use the most general density matrix equations to calculate the temperature evolution of flavoured leptonic asymmetry. A simplified analytical solution of these equations, applicable to the RH neutrino spectrum predicted in the model, is also obtained which allows one to fit the observed baryon to photon ratio along with the other fermion mass observables in a numerically efficient way. The analytical and numerical solutions are found to be in agreement within a factor of $$ \mathcal{O}(1) $$ O 1 . We find that the successful leptogenesis in this model does not prefer any particular value for leptonic Dirac and Majorana CP phases and the entire range of values of these observables is found to be consistent. The model specifically predicts (a) the lightest neutrino mass $$ {m}_{v_1} $$ m v 1 between 2–8 meV, (b) the effective mass of neutrinoless double beta decay mββ between 4–10 meV, and (c) a particular correlation between the Dirac and one of the Majorana CP phases.

scholarly journals FERMION MASS IN THE WILSON-YUKAWA APPROACH FOR CHIRAL YUKAWA THEORY

1994 ◽  
Vol 09 (26) ◽  
pp. 4565-4580
Author(s):  
SINYA AOKI ◽  
YOSHIO KIKUKAWA
Keyword(s):  
Vacuum Expectation ◽  
Vacuum Expectation Value ◽  
Fermion Mass ◽  
Yukawa Model ◽  
Expectation Value ◽  
Higgs Vacuum ◽  
Fermion Fields ◽  
Scalar Action ◽  
External Gauge ◽  
The Continuum

We consider a modification of the Wilson-Yukawa model to overcome the difficulty that the fermion mass is not proportional to the Higgs vacuum expectation value. In the modification scalar and fermionic regulator fields are introduced so that all the physical fermion fields possess shift symmetry when the Yukawa coupling vanishes. With the fermionic hopping parameter expansion it is shown that the fermion mass is proportional to the Higgs vacuum expectation value. We find, however, that the coupling of fermion to the external gauge field is always vectorlike in the continuum limit and that further modifications to the scalar action cannot change this undesirable conclusion.

scholarly journals K0-K¯0 Mixing in the Minimal Flavor-Violating Two-Higgs-Doublet Models

2017 ◽  
Vol 2017 ◽  
pp. 1-15 ◽  
Author(s):  
Natthawin Cho ◽  
Xin-Qiang Li ◽  
Fang Su ◽  
Xin Zhang
Keyword(s):  
Mass Difference ◽  
Vacuum Expectation ◽  
Vacuum Expectation Value ◽  
Higgs Doublet ◽  
New Physics ◽  
Point Of View ◽  
Minimal Flavor Violation ◽  
Yukawa Couplings ◽  
Charged Higgs ◽  
Current Experimental Data

The two-Higgs-doublet model (2HDM), as one of the simplest extensions of the Standard Model (SM), is obtained by adding another scalar doublet to the SM and is featured by a pair of charged Higgs, which could affect many low-energy processes. In the “Higgs basis” for a generic 2HDM, only one scalar doublet gets a nonzero vacuum expectation value and, under the criterion of minimal flavor violation, the other one is fixed to be either color-singlet or color-octet, which are named as type III and type C 2HDM, respectively. In this paper, we study the charged-Higgs effects of these two models on the K0-K¯0 mixing, an ideal process to probe New Physics (NP) beyond the SM. Firstly, we perform a complete one-loop computation of the box diagrams relevant to the K0-K¯0 mixing, keeping the mass and momentum of the external strange quark up to the second order. Together with the up-to-date theoretical inputs, we then give a detailed phenomenological analysis, in the cases of both real and complex Yukawa couplings of the charged Higgs to quarks. The parameter spaces allowed by the current experimental data on the mass difference ΔmK and the CP-violating parameter ϵK are obtained and the differences between these two 2HDMs are investigated, which are helpful to distinguish them from each other from a phenomenological point of view.

scholarly journals The serendipity of electroweak baryogenesis

2018 ◽  
Vol 376 (2114) ◽  
pp. 20170124 ◽  
Author(s):  
Géraldine Servant
Keyword(s):  
Particle Physics ◽  
Dipole Moments ◽  
Vacuum Expectation ◽  
Vacuum Expectation Value ◽  
Yukawa Couplings ◽  
Composite Higgs ◽  
The Standard Model ◽  
The Right ◽  
Right Order ◽  
The Universe

The origin of the matter–antimatter asymmetry of the universe remains unexplained in the Standard Model (SM) of particle physics. The origin of the flavour structure is another major puzzle of the theory. In this article, we report on recent work attempting to link the two themes through the appealing framework of electroweak (EW) baryogenesis. We show that Yukawa couplings of SM fermions can be the source of CP violation for EW baryogenesis if they vary at the same time as the Higgs is acquiring its vacuum expectation value, offering new avenues for EW baryogenesis. The advantage of this approach is that it circumvents the usual severe bounds from electric dipole moments. These ideas apply if the mechanism explaining the flavour structure of the SM is connected to EW symmetry breaking, as motivated for instance in Randall–Sundrum or Composite Higgs models. We compute the resulting baryon asymmetry for different configurations of the Yukawa coupling variation across the bubble wall and show that it can naturally be of the right order. This article is part of the Theo Murphy meeting issue ‘Higgs cosmology’.

scholarly journals DIRAC NEUTRINO MASSES AND MIXING PARAMETERS IN A LEFT–RIGHT MODEL WITH MIRROR FERMIONS

2007 ◽  
Vol 22 (16n17) ◽  
pp. 2935-2943 ◽  
Author(s):  
R. GAITÁN ◽  
A. HERNÁNDEZ-GALEANA ◽  
J. M. RIVERA-REBOLLEDO ◽  
P. FERNÁNDEZ DE CÓRDOBA ◽  
S. RODRIGUEZ-ROMO
Keyword(s):  
Vacuum Expectation ◽  
Vacuum Expectation Value ◽  
Neutrino Masses ◽  
Neutrino Mixing ◽  
Mixing Angles ◽  
Expectation Value ◽  
Mixing Parameters ◽  
Order Of Magnitude ◽  
Free Parameters ◽  
The Masses

In this work we consider a left–right model containing mirror fermions with gauge group SU (3)C ⊗ SU (2)L ⊗ SU (2)R ⊗ U (1)Y′. The model has several free parameters which here we have calculated by using the recent values for the squared-neutrino mass differences. Lower bound for the mirror vacuum expectation value helped us to obtain crude estimations for some of these parameters. Also we estimate the order of magnitude of the masses of the standard and mirror neutrinos and numerical values for neutrino mixing angles.

THE FERMION MASSES IN E6

1998 ◽  
Vol 13 (09) ◽  
pp. 685-693
Author(s):  
H. AKCAY
Keyword(s):  
Mass Spectrum ◽  
Grand Unification ◽  
Neutrino Masses ◽  
Yukawa Couplings ◽  
Neutrino Spectrum ◽  
Fermion Masses ◽  
The Masses

We investigate a particular breaking chain of the grand unification group E6. With two smallest Higgs multiplets that have Yukawa couplings to fermions, we obtain a reasonable mass spectrum for fermions. The neutrino masses are expressed in terms of the masses of the charged fermions, leading to a predictive neutrino spectrum.

scholarly journals R-symmetric flipped SU(5)

2020 ◽  
Vol 2020 (11) ◽  
Author(s):  
Koichi Hamaguchi ◽  
Shihwen Hor ◽  
Natsumi Nagata
Keyword(s):  
Scale Up ◽  
Higgs Field ◽  
Vacuum Expectation ◽  
Vacuum Expectation Value ◽  
Large Mass ◽  
Proton Decay ◽  
Decay Modes ◽  
Splitting Problem ◽  
The Masses ◽  
Higgs Fields

Abstract We construct a supersymmetric flipped SU(5) grand unified model that possesses an R symmetry. This R symmetry forbids dangerous non-renormalizable operators suppressed by a cut-off scale up to sufficiently large mass dimensions so that the SU(5)-breaking Higgs field develops a vacuum expectation value of the order of the unification scale along the F- and D-flat directions, with the help of the supersymmetry-breaking effect. The mass terms of the Higgs fields are also forbidden by the R symmetry, with which the doublet-triplet splitting problem is solved with the missing partner mechanism. The masses of right-handed neutrinos are generated by non-renormalizable operators, which then yield a light neutrino mass spectrum and mixing through the seesaw mechanism that are consistent with neutrino oscillation data. This model predicts one of the color-triplet Higgs multiplets to lie at an intermediate scale, and its mass is found to be constrained by proton decay experiments to be ≳ 5 × 1011 GeV. If it is ≲ 1012 GeV, future proton decay experiments at Hyper-Kamiokande can test our model in the p → π0μ+ and p → K0μ+ decay modes, in contrast to ordinary grand unified models where p → π0e+ or p → $$ {K}^{+}\overline{\nu} $$ K + ν ¯ is the dominant decay mode. This characteristic prediction for the proton decay branches enables us to distinguish our model from other scenarios.

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