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 Muon and electron g − 2 and the origin of the fermion mass hierarchy

2020 ◽  
Vol 2020 (9) ◽  
Author(s):  
Naoyuki Haba ◽  
Yasuhiro Shimizu ◽  
Toshifumi Yamada
Keyword(s):  
Charged Lepton ◽  
Higgs Sector ◽  
Vacuum Expectation ◽  
Fermion Mass ◽  
Mass Hierarchy ◽  
Lepton Flavor Violation ◽  
Scalar Particles ◽  
Lepton Flavor ◽  
Flavor Violation ◽  
Charged Leptons

Abstract We present a model that gives a natural explanation to the charged lepton mass hierarchy and study the contributions to the electron and the muon $g-2$. In the model, we introduce lepton-flavor-dependent $U(1)_F$ symmetry and three additional Higgs doublets with $U(1)_F$ charges, to realize that each generation of charged leptons couples to one of the three additional Higgs doublets. The $U(1)_F$ symmetry is softly broken by $+1$ charges, and the smallness of the soft breaking naturally gives rise to the hierarchy of the Higgs vacuum expectation values, which then accounts for the charged lepton mass hierarchy. Since electron and muon couple to different scalar particles, each scalar contributes to the electron and the muon $g-2$ differently. We survey the space of parameters of the Higgs sector and find that there are sets of parameters that explain the muon $g-2$ discrepancy. On the other hand, we cannot find parameter sets that can explain the $g-2$ discrepancy within 2 $\sigma$. Here, the $U(1)_F$ symmetry suppresses charged lepton flavor violation.

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 Evidence of the big fix

2014 ◽  
Vol 29 (17) ◽  
pp. 1450099 ◽  
Author(s):  
Yuta Hamada ◽  
Hikaru Kawai ◽  
Kiyoharu Kawana
Keyword(s):  
Maximum Entropy Principle ◽  
Vacuum Expectation ◽  
Vacuum Expectation Value ◽  
Baryon Number ◽  
Quark Masses ◽  
Atomic Nuclei ◽  
The Standard Model ◽  
Entropy Principle ◽  
Fundamental Law ◽  
The Universe

We give an evidence of the Big Fix. The theory of wormholes and multiverse suggests that the parameters of the Standard Model are fixed in such a way that the total entropy at the late stage of the universe is maximized, which we call the maximum entropy principle. In this paper, we discuss how it can be confirmed by the experimental data, and we show that it is indeed true for the Higgs vacuum expectation value vh. We assume that the baryon number is produced by the sphaleron process, and that the current quark masses, the gauge couplings and the Higgs self-coupling are fixed when we vary vh. It turns out that the existence of the atomic nuclei plays a crucial role to maximize the entropy. This is reminiscent of the anthropic principle, however it is required by the fundamental law in our case.

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 MUON ANOMALY AND A LOWER BOUND ON HIGGS MASS DUE TO A LIGHT STABILIZED RADION IN THE RANDALL–SUNDRUM MODEL

2006 ◽  
Vol 21 (26) ◽  
pp. 5205-5220 ◽  
Author(s):  
PRASANTA KUMAR DAS
Keyword(s):  
Lower Bound ◽  
Extra Dimension ◽  
Higgs Mass ◽  
Vacuum Expectation ◽  
Vacuum Expectation Value ◽  
Quartic Coupling ◽  
Muon Anomalous Magnetic Moment ◽  
Expectation Value ◽  
The Standard Model ◽  
Standard Model Result

We investigate the Randall–Sundrum model with a light stabilized radion (required to fix the size of the extra dimension) in the light of muon anomalous magnetic moment [Formula: see text]. Using the recent data (obtained from the E821 experiment of the BNL Collaboration) which differs by 2.6σ from the Standard Model result, we obtain constraints on radion mass mϕ and radion vacuum expectation value 〈ϕ〉. In the presence of a radion the beta functions β(λ) and β(gt) of Higgs quartic coupling (λ) and top-Yukawa coupling (gt) gets modified. We find these modified beta functions. Using these beta functions together with the anomaly constrained mϕ and 〈ϕ〉, we obtain lower bound on Higgs mass mh. We compare our result with the present LEP2 bound on mh.

scholarly journals Unified emergence of energy scales and cosmic inflation

2021 ◽  
Vol 2021 (8) ◽  
Author(s):  
Jisuke Kubo ◽  
Jeffrey Kuntz ◽  
Manfred Lindner ◽  
Jonas Rezacek ◽  
Philipp Saake ◽  
...  
Keyword(s):  
Scale Invariance ◽  
Planck Scale ◽  
Vacuum Expectation ◽  
Vacuum Expectation Value ◽  
Spontaneous Breaking ◽  
Type I ◽  
Cosmic Inflation ◽  
Dynamical Generation ◽  
Majorana Neutrinos ◽  
Relic Abundance

Abstract In the quest for unification of the Standard Model with gravity, classical scale invariance can be utilized to dynamically generate the Planck mass MPl. However, the relation of Planck scale physics to the scale of electroweak symmetry breaking μH requires further explanation. In this paper, we propose a model that uses the spontaneous breaking of scale invariance in the scalar sector as a unified origin for dynamical generation of both scales. Using the Gildener-Weinberg approximation, only one scalar acquires a vacuum expectation value of υS ∼ (1016−17) GeV, thus radiatively generating $$ {M}_{\mathrm{P}1}\approx {\beta}_S^{1/2}{\upsilon}_S $$ M P 1 ≈ β S 1 / 2 υ S and μH via the neutrino option with right handed neutrino masses mN = yMυS ∼ 107 GeV. Consequently, active SM neutrinos are given a mass with the inclusion of a type-I seesaw mechanism. Furthermore, we adopt an unbroken Z2 symmetry and a Z2-odd set of right-handed Majorana neutrinos χ that do not take part in the neutrino option and are able to produce the correct dark matter relic abundance (dominantly) via inflaton decay. The model also describes cosmic inflation and the inflationary CMB observables are predicted to interpolate between those of R2 and linear chaotic inflationary model and are thus well within the strongest experimental constraints.

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 Quark mass hierarchy and mixing via geometry of extra dimension with point interactions

2013 ◽  
Vol 2013 (2) ◽  
Author(s):  
Yukihiro Fujimoto ◽  
Tomoaki Nagasawa ◽  
Kenji Nishiwaki ◽  
Makoto Sakamoto
Keyword(s):  
Extra Dimension ◽  
Quark Mass ◽  
Mass Hierarchy ◽  
Point Interactions

scholarly journals A scalar potential from gauge condensation and its implications

2020 ◽  
Vol 80 (10) ◽  
Author(s):  
Eung Jin Chun ◽  
Chengcheng Han
Keyword(s):  
Scalar Potential ◽  
Vacuum Expectation ◽  
Vacuum Expectation Value ◽  
New Physics ◽  
Kinetic Term ◽  
Electroweak Symmetry ◽  
Abelian Gauge ◽  
Gauge Sector ◽  
Dynamical Generation ◽  
Shed Light

AbstractWe consider a scalar field $$\phi $$ ϕ whose coupling to the kinetic term of a non-abelian gauge field is set at an UV scale M. Then the confinement of the gauge sector will induce a $$\phi $$ ϕ -dependent vacuum energy which generates a dimensionful potential for the scalar. It provides a good example of dynamical generation of a new physics scale below M through the vacuum expectation value $$\langle \phi \rangle $$ ⟨ ϕ ⟩ . This mechanism may shed light on the origin of dark matter, or spontaneous symmetry breaking applicable to the electroweak symmetry.

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