scholarly journals Fermion mass hierarchy from nonuniversal Abelian extensions of the standard model

2018 ◽  
Vol 98 (1) ◽  
Author(s):  
Carlos E. Diaz ◽  
S. F. Mantilla ◽  
R. Martinez
Keyword(s):  
Standard Model ◽  
Fermion Mass ◽  
Mass Hierarchy ◽  
Abelian Extensions ◽  
The Standard Model

scholarly journals A bottom-up approach to fermion mass hierarchy: a case with vector-like fermions

2020 ◽  
Vol 2020 (4) ◽  
Author(s):  
Yoshiharu Kawamura
Keyword(s):  
Standard Model ◽  
Yukawa Coupling ◽  
High Energy ◽  
Fine Tuning ◽  
Fermion Mass ◽  
Extended Model ◽  
Mass Hierarchy ◽  
Bottom Up ◽  
Existence Proofs ◽  
The Standard Model

Abstract We propose a bottom-up approach in which a structure of high-energy physics is explored by accumulating existence proofs and/or no-go theorems in the standard model or its extension. As an illustration, we study fermion mass hierarchies based on an extension of the standard model with vector-like fermions. It is shown that the magnitude of elements of Yukawa coupling matrices can become $O(1)$ and a Yukawa coupling unification can be realized in a theory beyond the extended model, if vector-like fermions mix with three families. In this case, small Yukawa couplings in the standard model can be highly sensitive to a small variation of matrix elements, and it seems that the mass hierarchy occurs as a result of fine tuning.

scholarly journals A unified Yukawa interaction for the Standard Model of quarks and leptons

2021 ◽  
Vol 36 (27) ◽  
pp. 2150196
Author(s):  
Ying Zhang
Keyword(s):  
Standard Model ◽  
Mass Matrix ◽  
Fermion Mass ◽  
Mass Hierarchy ◽  
Yukawa Interaction ◽  
Flavor Structure ◽  
Fermion Masses ◽  
The Standard Model ◽  
Matrix Formula

To address fermion mass hierarchy and flavor mixings in the quark and lepton sectors, a minimal flavor structure without any redundant parameters beyond phenomenological observables is proposed via decomposition of the Standard Model Yukawa mass matrix into a bi-unitary form. After reviewing the roles and parameterization of the factorized matrix [Formula: see text] and [Formula: see text] in fermion masses and mixings, we generalize the mechanism to up- and down-type fermions to unify them into a universal quark/lepton Yukawa interaction. In the same way, a unified form of the description of the quark and lepton Yukawa interactions is also proposed, which shows a similar picture as the unification of gauge interactions.

scholarly journals A first test of the framed standard model against experiment

2015 ◽  
Vol 30 (11) ◽  
pp. 1550051 ◽  
Author(s):  
José Bordes ◽  
Hong-Mo Chan ◽  
Sheung Tsun Tsou
Keyword(s):  
Standard Model ◽  
Mass Matrix ◽  
Internal Symmetry ◽  
Fermion Mass ◽  
Mass Hierarchy ◽  
Order Unity ◽  
Changing Scale ◽  
The Standard Model ◽  
Symmetry Space ◽  
Fermion Mass Matrix

The framed standard model (FSM) is obtained from the standard model by incorporating, as field variables, the frame vectors (vielbeins) in internal symmetry space. It gives the standard Higgs boson and 3 generations of quarks and leptons as immediate consequences. It gives moreover a fermion mass matrix of the form: m = mTαα†, where α is a vector in generation space independent of the fermion species and rotating with changing scale, which has already been shown to lead, generically, to up–down mixing, neutrino oscillations and mass hierarchy. In this paper, pushing the FSM further, one first derives to 1-loop order the RGE for the rotation of α, and then applies it to fit mass and mixing data as a first test of the model. With 7 real adjustable parameters, 18 measured quantities are fitted, most (12) to within experimental error or to better than 0.5 percent, and the rest (6) not far off. (A summary of this fit can be found in Table 2 of this paper.) Two notable features, both generic to FSM, not just specific to the fit, are: (i) that a theta-angle of order unity in the instanton term in QCD would translate via rotation into a Kobayashi–Maskawa phase in the CKM matrix of about the observed magnitude (J ~ 10-5), (ii) that it would come out correctly that mu < md, despite the fact that mt ≫ mb, mc ≫ ms. Of the 18 quantities fitted, 12 are deemed independent in the usual formulation of the standard model. In fact, the fit gives a total of 17 independent parameters of the standard model, but 5 of these have not been measured by experiment.

scholarly journals The framed Standard Model (II) — A first test against experiment

2015 ◽  
Vol 30 (30) ◽  
pp. 1530060
Author(s):  
Hong-Mo Chan ◽  
Sheung Tsun Tsou
Keyword(s):  
Standard Model ◽  
Renormalization Group Equation ◽  
Fermion Mass ◽  
Group Equation ◽  
Unknown Parameters ◽  
Mass Matrices ◽  
The Standard Model ◽  
Experimental Values ◽  
The Masses ◽  
Independent Parameters

Apart from the qualitative features described in Paper I (Ref. 1), the renormalization group equation derived for the rotation of the fermion mass matrices are amenable to quantitative study. The equation depends on a coupling and a fudge factor and, on integration, on 3 integration constants. Its application to data analysis, however, requires the input from experiment of the heaviest generation masses [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text] all of which are known, except for [Formula: see text]. Together then with the theta-angle in the QCD action, there are in all 7 real unknown parameters. Determining these 7 parameters by fitting to the experimental values of the masses [Formula: see text], [Formula: see text], [Formula: see text], the CKM elements [Formula: see text], [Formula: see text], and the neutrino oscillation angle [Formula: see text], one can then calculate and compare with experiment the following 12 other quantities [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], and the results all agree reasonably well with data, often to within the stringent experimental error now achieved. Counting the predictions not yet measured by experiment, this means that 17 independent parameters of the standard model are now replaced by 7 in the FSM.

scholarly journals THE DUALIZED STANDARD MODEL AND ITS APPLICATIONS — AN INTERIM REPORT

1999 ◽  
Vol 14 (14) ◽  
pp. 2173-2203 ◽  
Author(s):  
HONG-MO CHAN ◽  
SHEUNG TSUN TSOU
Keyword(s):  
Standard Model ◽  
High Energy ◽  
Fermion Mass ◽  
Mass Hierarchy ◽  
Matrix Elements ◽  
Ckm Matrix ◽  
High Energy Cosmic Rays ◽  
Perturbative Method ◽  
Ckm Matrix Elements ◽  
Physical Consequences

Based on a non-Abelian generalization of electric–magnetic duality, the Dualized Standard Model (DSM) suggests a natural explanation for exactly three generations of fermions as the "dual colour" [Formula: see text] symmetry broken in a particular manner. The resulting scheme then offers on the one hand a fermion mass hierarchy and a perturbative method for calculating the mass and mixing parameters of the Standard Model fermions, and on the other hand testable predictions for new phenomena ranging from rare meson decays to ultra-high energy cosmic rays. Calculations to one-loop order gives, at the cost of adjusting only three real parameters, values for the following quantities all (except one) in very good agreement with experiment: the quark CKM matrix elements ‖Vrs‖, the lepton CKM matrix elements ‖Urs‖, and the second generation masses mc, ms, mμ. This means, in particular, that it gives near maximal mixing Uμ3 between νμ and ντ as observed by SuperKamiokande, Kamiokande and Soudan, while keeping small the corresponding quark angles Vcb, Vts. In addition, the scheme gives (i) rough order-of-magnitude estimates for the masses of the lowest generation, (ii) predictions for low energy FCNC effects such as KL→ eμ, and (iii) a possible explanation for the long-standing puzzle of air showers beyond the GZK cut-off. All these together, however, still represent but a portion of the possible physical consequences derivable from the DSM scheme, the majority of which are yet to be explored.

scholarly journals The gravitational condensate of the higgs field

2019 ◽  
Author(s):  
Vitaly Kuyukov
Keyword(s):  
Higgs Boson ◽  
Standard Model ◽  
Higgs Field ◽  
Higgs Bosons ◽  
Grand Unification ◽  
Gravitational Potential Energy ◽  
Mass Hierarchy ◽  
The Standard Model ◽  
Cell Condensation ◽  
The Difference

This paper analyses a method of producing the Higgs mass via the gravitational field. This approach has become very popular in recent years, as the consideration of other forces do not help in solving the problem of mass hierarchy. Not understand the difference between scales of the standard model and Grand unification theory. Here, we present a heuristic mechanism which eliminated this difference. The idea is that the density of the condensate of the Higgs is increased so that it is necessary to take into account self gravitational potential energy of the Higgs boson. The result is as follows. The mass of the Higgs is directly proportional to the cell density of the Higgs bosons. Or else the mass of the Higgs is inversely proportional to the cell volume, which is the Higgs boson in the condensate. The most interesting dimension of this cell condensation is equal to the scale of Grand unification. This formula naturally combines the scale of the standard model and Grand unification through gravitational condensation.

scholarly journals THE UNIT OF ELECTRIC CHARGE AND THE MASS HIERARCHY OF HEAVY PARTICLES

2007 ◽  
Vol 22 (38) ◽  
pp. 2909-2916
Author(s):  
G. LÓPEZ CASTRO ◽  
J. PESTIEAU
Keyword(s):  
Standard Model ◽  
Mass Hierarchy ◽  
Empirical Formulas ◽  
Heavy Particles ◽  
The Standard Model ◽  
Experimental Values ◽  
The One ◽  
Simple Ratio ◽  
The Masses ◽  
Good Agreement

We propose some empirical formulas relating the masses of the heaviest particles in the standard model (the W, Z, H bosons and the t quark) to the charge of the positron e and the Higgs condensate v. The relations for the masses of gauge bosons mW = (1+e)v/4 and [Formula: see text] are in good agreement with experimental values. By requiring the electroweak standard model to be free from quadratic divergences at the one-loop level, we find: [Formula: see text] and [Formula: see text], or the very simple ratio (mt/mH)2 = e.

scholarly journals Quantum stabilization of cosmic strings

2015 ◽  
Vol 30 (27) ◽  
pp. 1530022 ◽  
Author(s):  
H. Weigel ◽  
M. Quandt ◽  
N. Graham
Keyword(s):  
Standard Model ◽  
Top Quark ◽  
Cosmic String ◽  
Bound States ◽  
Degrees Of Freedom ◽  
Energy Levels ◽  
Binding Energies ◽  
Fermion Mass ◽  
The Standard Model ◽  
A Charge

In the standard model, stabilization of a classically unstable cosmic string may occur through the quantum fluctuations of a heavy fermion doublet. We review numerical results from a semiclassical expansion in a reduced version of the standard model. In this expansion, the leading quantum corrections emerge at one loop level for many internal degrees of freedom. The resulting vacuum polarization energy and the binding energies of occupied fermion energy levels are of the same order, and must therefore be treated on equal footing. Populating these bound states lowers the total energy compared to the same number of free fermions and assigns a charge to the string. Charged strings are already stabilized for a fermion mass only somewhat larger than the top quark mass. Though obtained in a reduced version, these results suggest that neither extraordinarily large fermion masses nor unrealistic couplings are required to bind a cosmic string in the standard model. Furthermore, we also review results for a quantum stabilization mechanism that prevents closed Nielsen–Olesen-type strings from collapsing.

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