scholarly journals The Family Formula for Leptons and Quarks

2019 ◽  
Author(s):  
Nikola Perkovic
Keyword(s):  
Structure Constant ◽  
Vacuum Expectation ◽  
Vacuum Expectation Value ◽  
Majorana Neutrino ◽  
Fine Structure Constant ◽  
Dirac Fermions ◽  
Strong Argument ◽  
Yukawa Couplings ◽  
Charged Leptons ◽  
G Factors

The problem of Yukawa couplings being arbitrary parameters in the Standard Model Higgs mechanism is a long standing one due to their formulaic dependence on the Higgs Vacuum Expectation Value. We will attempt to solve this problem and provide a strong argument that the Yukawa couplings of charged leptons and down type quarks are not arbitrary parameters in the SM. A new methodology for predicting the Yukawa couplings will be presented by using Compton wavelengths, the Rydberg Constant and g-factors of charged leptons instead of relying on the Higgs VEV. We will then proceed to rewrite this new method in terms of an empirical formula that depends on the running of the fine-structure constant on the Q scale, charge and lepton quantum numbers and g-factors to predict the values of the Yukawa couplings for all three generations of charged leptons and d-type quarks. We will also touch on the subject of neutrinos both as Majorana and Dirac fermions respectively and make a prediction for the lightest possible Majorana neutrino and the differences between Dirac neutrinos and anti-neutrinos. We conclude that the Yukawa couplings are not arbitrary parameters in the SM and that this new formula provides very accurate results.

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 Dynamical generation of quark/lepton mass hierarchy in an extra dimension

2019 ◽  
Vol 2019 (12) ◽  
Author(s):  
Yukihiro Fujimoto ◽  
Kouhei Hasegawa ◽  
Kenji Nishiwaki ◽  
Makoto Sakamoto ◽  
Kazunori Takenaga ◽  
...  
Keyword(s):  
Extra Dimension ◽  
Vacuum Expectation ◽  
Vacuum Expectation Value ◽  
Casimir Energy ◽  
Mass Hierarchy ◽  
Point Interactions ◽  
Quark Masses ◽  
Dynamical Generation ◽  
Charged Leptons ◽  
Experimental Values

Abstract We show that the observed quark/lepton mass hierarchy can be realized dynamically on an interval extra dimension with point interactions. In our model, the positions of the point interactions play a crucial role in controlling the quark/lepton mass hierarchy and are determined by the minimization of the Casimir energy. By use of the exact extra-dimensional coordinate-dependent vacuum expectation value of a gauge-singlet scalar, we find that there is a parameter set, where the positions of the point interactions are stabilized and fixed, which can reproduce the experimental values of the quark masses precisely enough, while the charged lepton part is less relevant. We also show that possible mixings among the charged leptons will improve the situation significantly.

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 Modular $S_3$-invariant flavor model in SU(5) grand unified theory

2020 ◽  
Vol 2020 (5) ◽  
Author(s):  
Tatsuo Kobayashi ◽  
Yusuke Shimizu ◽  
Kenta Takagi ◽  
Morimitsu Tanimoto ◽  
Takuya H. Tatsuishi
Keyword(s):  
Modular Forms ◽  
Vacuum Expectation ◽  
Vacuum Expectation Value ◽  
Double Beta Decay ◽  
Unified Theory ◽  
Grand Unified Theory ◽  
Mass Matrices ◽  
Charge Parity ◽  
Charged Leptons ◽  
Leptonic Charge

Abstract We present a flavor model with $S_3$ modular invariance in the framework of SU(5) grand unified theory (GUT). The $S_3$ modular forms of weights $2$ and $4$ give the quark and lepton mass matrices with a common complex parameter, the modulus $\tau$. The GUT relation of down-type quarks and charged leptons is imposed by the vacuum expectation value (VEV) of the adjoint 24-dimensional Higgs multiplet in addition to the VEVs of $5$ and $\bar 5$ Higgs multiplets of SU(5). The observed Cabibbo–Kobayashi–Maskawa and Pontecorvo–Maki–Nakagawa–Sakata mixing parameters as well as the mass eigenvalues are reproduced properly. We discuss the leptonic charge–parity phase and the effective mass of the neutrinoless double beta decay with the sum of neutrino masses.

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’.

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