scholarly journals Flavored axion in the UV-complete Froggatt–Nielsen models

2021 ◽  
Vol 81 (7) ◽  
Author(s):  
Leon M. G. de la Vega ◽  
Newton Nath ◽  
Stefan Nellen ◽  
Eduardo Peinado
Keyword(s):  
Fermion Mass ◽  
Leading Order ◽  
Interaction Structure ◽  
Neutrino Sector ◽  
Quark Sector ◽  
Fermion Masses ◽  
Mass Matrices ◽  
The Standard Model ◽  
Photon Coupling ◽  
Neighbour Interaction

AbstractWe propose UV-completions of Froggatt–Nielsen–Peccei–Quinn models of fermion masses and mixings with flavored axions, by incorporating heavy fields. Here, the U(1) Froggatt–Nielsen symmetry is identified with the Peccei–Quinn symmetry to solve the strong CP problem along with the mass hierarchies of the Standard Model fermions. We take into account leading order contributions to the fermion mass matrices giving rise to Nearest-Neighbour-Interaction structure in the quark sector and $$A_2$$ A 2 texture in the neutrino sector. A comprehensive numerical analysis has been performed for the fermion mass matrices. Subsequently, we investigate the resulting axion flavor violating couplings and the axion-photon coupling arising from the model.

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 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 hierarchy in grand gauge-Higgs unification

2019 ◽  
Vol 2019 (8) ◽  
Author(s):  
Nobuhito Maru ◽  
Yoshiki Yatagai
Keyword(s):  
Top Quark ◽  
Electroweak Symmetry Breaking ◽  
Boson Mass ◽  
Fermion Mass ◽  
Mass Hierarchy ◽  
Electroweak Symmetry ◽  
Fermion Masses ◽  
The Standard Model ◽  
Mass Terms ◽  
The One

Abstract Grand gauge-Higgs unification of 5D $SU(6)$ gauge theory on an orbifold $S^1/Z_2$ is discussed. The Standard Model (SM) fermions are introduced on one of the boundaries and some massive bulk fields are also introduced so that they couple to the SM fermions through the mass terms on the boundary. Integrating out the bulk fields generates SM fermion masses with exponentially small bulk mass dependences. The SM fermion masses except for the top quark are shown to be reproduced by mild tuning of the bulk masses. The one-loop Higgs potential is calculated and it is shown that electroweak symmetry breaking occurs by introducing additional bulk fields. The Higgs boson mass is also computed.

B−L model based on Q4 symmetry for fermion spectrum with normal neutrino mass ordering

2021 ◽  
Vol 36 (07) ◽  
pp. 2150047
Author(s):  
V. V. Vien
Keyword(s):  
Neutrino Mass ◽  
Type I ◽  
Effective Parameters ◽  
Seesaw Mechanism ◽  
Mixing Angle ◽  
Mixing Angles ◽  
Neutrino Sector ◽  
Quark Sector ◽  
The Standard Model ◽  
Experimental Values

We propose a renormalizable gauge [Formula: see text] extension of the Standard Model (SM) based on [Formula: see text] symmetry and an auxiliary [Formula: see text] symmetry which can explain the observed quark and lepton masses and mixing angles associated to normal neutrino mass ordering through type-I seesaw mechanism. The relation between the atmospheric mixing angle [Formula: see text] and the effective parameters in neutrino sector is analyzed. Two Majorana phases are predicted to be [Formula: see text] and [Formula: see text] and the model also predicts the effective neutrino mass parameters of [Formula: see text], [Formula: see text] which is well consistent with the planning of future experiments. In the quark sector, the model is predictive since it has ten effective parameters that allow to successfully reproduce the experimental values of the experimental values of the ten physical observables of the quark sector.

A DETAILED ACCOUNT OF ALAIN CONNES' VERSION OF THE STANDARD MODEL IN NON-COMMUTATIVE GEOMETRY: I AND II.

1993 ◽  
Vol 05 (03) ◽  
pp. 477-532 ◽  
Author(s):  
DANIEL KASTLER
Keyword(s):  
Standard Model ◽  
Coupling Constants ◽  
Fermion Mass ◽  
Detailed Calculation ◽  
Coupling Constant ◽  
Electroweak Interactions ◽  
Symmetrical Form ◽  
Mass Matrices ◽  
The Standard Model ◽  
Universal Coupling

We present a detailed calculation of the Lagrangian of the standard model prescribed in the paper [4] of Connes and Lott, first for the electroweak interactions alone, and then (as is necessary to achieve the correct weak hypercharge assignments) for the coupling of electroweak interactions with chromodynamics. In its most symmetrical form (with free parameters the fermion mass-matrices plus one universal coupling constant), the Connes theory in tree-approximation yields equality of the strong and electroweak coupling constants, and fixes the value sin 2 θw = 3/8, and the ratios mt/mw and mH/mt.

scholarly journals Has the origin of the third-family fermion masses been determined?

2021 ◽  
Vol 2021 (4) ◽  
Author(s):  
Michael J. Baker ◽  
Peter Cox ◽  
Raymond R. Volkas
Keyword(s):  
Precision Measurements ◽  
Tree Level ◽  
Fermion Mass ◽  
Mass Generation ◽  
Quark Masses ◽  
The Third ◽  
Fermion Masses ◽  
The Standard Model ◽  
First Time ◽  
Rule Out

Abstract Precision measurements of the Higgs couplings are, for the first time, directly probing the mechanism of fermion mass generation. The purpose of this work is to determine to what extent these measurements can distinguish between the tree-level mechanism of the Standard Model and the theoretically motivated alternative of radiative mass generation. Focusing on the third-family, we classify the minimal one-loop models and find that they fall into two general classes. By exploring several benchmark models in detail, we demonstrate that a radiative origin for the tau-lepton and bottom-quark masses is consistent with current observations. While future colliders will not be able to rule out a radiative origin, they can probe interesting regions of parameter space.

scholarly journals SU(5)×U(1)′ Models with a Vector-Like Fermion Family

Universe ◽  
2021 ◽  
Vol 7 (10) ◽  
pp. 356
Author(s):  
A. Karozas ◽  
G. K. Leontaris ◽  
I. Tavellaris
Keyword(s):  
B Meson ◽  
Low Energy ◽  
Fermion Mass ◽  
Anomaly Cancellation ◽  
Covering Group ◽  
Geometric Singularity ◽  
Mass Matrices ◽  
The Standard Model ◽  
Model Predictions

Motivated by experimental measurements indicating deviations from the Standard Model predictions, we discuss F-theory-inspired models, which, in addition to the three chiral generations, contain a vector-like complete fermion family. The analysis takes place in the context of $SU(5)\times U(1)'$ GUT embedded in an $E_8$ covering group, which is associated with the (highest) geometric singularity of the elliptic fibration. In this context, the $U(1)'$ is a linear combination of four abelian factors subjected to the appropriate anomaly cancellation conditions. Furthermore, we require universal $U(1)'$ charges for the three chiral families and different ones for the corresponding fields of the vector-like representations. Under the aforementioned assumptions, we find 192 models that can be classified into five distinct categories with respect to their specific GUT properties. We exhibit representative examples for each such class and construct the superpotential couplings and the fermion mass matrices. We explore the implications of the vector-like states in low-energy phenomenology, including the predictions regarding the B-meson anomalies. The rôle of R-parity violating terms appearing in some particular models of the above construction is also discussed.

scholarly journals Dark matter and lepton flavour phenomenology in a singlet-doublet scotogenic model

2021 ◽  
Vol 2021 (12) ◽  
Author(s):  
Maud Sarazin ◽  
Jordan Bernigaud ◽  
Björn Herrmann
Keyword(s):  
Dark Matter ◽  
Higgs Mass ◽  
Cold Dark Matter ◽  
Monte Carlo Algorithm ◽  
Neutrino Masses ◽  
Neutrino Sector ◽  
Fermion Masses ◽  
The Standard Model ◽  
Future Collider ◽  
Lepton Flavour

Abstract We study the dark matter phenomenology of scotogenic frameworks through a rather illustrative model extending the Standard Model by scalar and fermionic singlets and doublets. Such a setup is phenomenologically attractive since it provides the radiative generation of neutrino masses, while also including viable candidates for cold dark matter. We employ a Markov Chain Monte Carlo algorithm to explore the associated parameter space in view of numerous constraints stemming from the Higgs mass, the neutrino sector, dark matter, and lepton-flavour violating processes. After a general discussion of the results, we focus on the case of fermionic dark matter, which remains rather uncovered in the literature so far. We discuss the associated phenomenology and show that in this particular case a rather specific mass spectrum is expected with fermion masses just above 1 TeV. Our study may serve as a guideline for future collider studies.

scholarly journals Parity and the origin of neutrino mass

2020 ◽  
Vol 35 (09) ◽  
pp. 2050053
Author(s):  
Goran Senjanović ◽  
Vladimir Tello
Keyword(s):  
Neutrino Mass ◽  
Mass Matrix ◽  
Spontaneous Breaking ◽  
Symmetric Model ◽  
Hadron Colliders ◽  
Seesaw Mechanism ◽  
Fermion Masses ◽  
Mass Matrices ◽  
The Standard Model ◽  
Complete Analogy

In the LHC era the issue of the origin and nature of neutrino mass has attained a new meaning and a renewed importance. The growing success of the Higgs–Weinberg mechanism behind the charged fermion masses paves the way for answering the question of neutrino mass. We have shown recently how the spontaneous breaking of parity in the context of the minimal left–right symmetric model allows to probe the origin of neutrino mass in complete analogy with the charged fermions masses in the Standard Model. We revisit here this issue and fill in the gaps left in our previous work. In particular we discuss a number of different mathematical approaches to the problem of disentangling the seesaw mechanism and show how a unique analytical solution emerges. Most important, we give all the possible expressions for the neutrino Dirac mass matrix for general values of light and heavy neutrino mass matrices. In practical terms what is achieved is an untangling of the seesaw mechanism with clear and precise predictions testable at hadron colliders such as LHC.

scholarly journals APPROXIMATE FLAVOR SYMMETRIES AT A GRAND UNIFICATION SCALE

1996 ◽  
Vol 11 (12) ◽  
pp. 965-971
Author(s):  
D. GÓMEZ DUMM
Keyword(s):  
Standard Model ◽  
Higgs Doublet ◽  
Grand Unification ◽  
Fermion Mass ◽  
Flavor Symmetries ◽  
Mass Matrices ◽  
The Standard Model ◽  
The Hierarchical Structure ◽  
Doublet Model ◽  
Two Higgs Doublet Model

We study the evolution of fermion mass matrices considering the hypothesis of approximate flavor symmetries (AFS) in the standard model and a two-Higgs-doublet model. We find that the hierarchical structure is not significantly altered by the running, hence the assumption of AFS is entirely compatible with a grand unification scenario.

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