scholarly journals Family gauge bosons with an inverted mass hierarchy

2012 ◽  
Vol 711 (5) ◽  
pp. 384-389 ◽  
Author(s):  
Yoshio Koide ◽  
Toshifumi Yamashita
Keyword(s):  
2012 ◽  
Author(s):  
Yoshio Koide ◽  
Toshifumi Yamashita
Keyword(s):  

2020 ◽  
Vol 2020 (9) ◽  
Author(s):  
Yoo-Jin Kang ◽  
Soonbin Kim ◽  
Hyun Min Lee

Abstract We consider various bulk fields with general dilaton couplings in the linear dilaton background in five dimensions as the continuum limit of clockwork models. We show that the localization of the zero modes of bulk fields and the mass gap in the KK spectrum depend not only on the bulk dilaton coupling, but also on the bulk mass parameter in the case of a bulk fermion. The consistency from universality and perturbativity of gauge couplings constrain the dilaton couplings to the brane-localized matter fields as well as the bulk gauge bosons. Constructing the Clockwork Standard Model (SM) in the linear dilaton background, we provide the necessary conditions for the bulk mass parameters for explaining the mass hierarchy and mixing for the SM fermions. We can introduce a sizable expansion parameter ε = $$ {e}^{-\frac{2}{3}{kz}_c} $$ e − 2 3 kz c for the realistic flavor structure in the quark sector without a fine-tuning in the bulk mass parameters, but at the expense of a large 5D Planck scale. On the other hand, we can use a smaller expansion parameter for lepton masses, in favor of the solution to the hierarchy problem of the Higgs mass parameter. We found that massive Kaluza-Klein (KK) gauge bosons and massive KK gravitons couple more strongly to light and heavy fermions, respectively, so there is a complementarity in the resonance researches for those KK modes at the LHC.


1999 ◽  
Vol 14 (32) ◽  
pp. 2223-2228 ◽  
Author(s):  
A. A. MACHADO ◽  
F. PISANO

Flavor dynamics chiral models of leptoquark fermions and bilepton gauge bosons with masses up to a few TeV, although coincident with physics of the Fermi scale standard model, address the fermion mass hierarchy and explain the flavor question. The presence of charged right-handed weak currents coupled to bileptons, which we point out here, is another feature of these chiral semisimple gauge theories.


2015 ◽  
Vol 30 (03) ◽  
pp. 1550017
Author(s):  
Yoshio Koide

When we try to consider family gauge bosons with a lower energy scale, a major obstacle is constraints from the observed [Formula: see text] mixings [Formula: see text]. Against such a conventional view, we point out that, in a U(3) family gauge boson model, the bosons are harmless to any [Formula: see text] mixings independently of explicit values of the family mixings, if masses Mij of the gauge bosons [Formula: see text] (i, j are family indexes) satisfy a relation [Formula: see text]. If such the case can be realized together with an inverted mass hierarchy [Formula: see text], we can consider family gauge bosons with a considerably lower scale, so that we can expect rich signs for family gauge bosons in a TeV scale.


2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Pilar Coloma ◽  
M. C. Gonzalez-Garcia ◽  
Michele Maltoni

Abstract We quantify the effect of gauge bosons from a weakly coupled lepton flavor dependent U(1)′ interaction on the matter background in the evolution of solar, atmospheric, reactor and long-baseline accelerator neutrinos in the global analysis of oscillation data. The analysis is performed for interaction lengths ranging from the Sun-Earth distance to effective contact neutrino interactions. We survey ∼ 10000 set of models characterized by the six relevant fermion U(1)′ charges and find that in all cases, constraints on the coupling and mass of the Z′ can be derived. We also find that about 5% of the U(1)′ model charges lead to a viable LMA-D solution but this is only possible in the contact interaction limit. We explicitly quantify the constraints for a variety of models including $$ \mathrm{U}{(1)}_{B-3{L}_e} $$ U 1 B − 3 L e , $$ \mathrm{U}{(1)}_{B-3{L}_{\mu }} $$ U 1 B − 3 L μ , $$ \mathrm{U}{(1)}_{B-3{L}_{\tau }} $$ U 1 B − 3 L τ , $$ \mathrm{U}{(1)}_{B-\frac{3}{2}\left({L}_{\mu }+{L}_{\tau}\right)} $$ U 1 B − 3 2 L μ + L τ , $$ \mathrm{U}{(1)}_{L_e-{L}_{\mu }} $$ U 1 L e − L μ , $$ \mathrm{U}{(1)}_{L_e-{L}_{\tau }} $$ U 1 L e − L τ , $$ \mathrm{U}{(1)}_{L_e-\frac{1}{2}\left({L}_{\mu }+{L}_{\tau}\right)} $$ U 1 L e − 1 2 L μ + L τ . We compare the constraints imposed by our oscillation analysis with the strongest bounds from fifth force searches, violation of equivalence principle as well as bounds from scattering experiments and white dwarf cooling. Our results show that generically, the oscillation analysis improves over the existing bounds from gravity tests for Z′ lighter than ∼ 10−8→ 10−11 eV depending on the specific couplings. In the contact interaction limit, we find that for most models listed above there are values of g′ and MZ′ for which the oscillation analysis provides constraints beyond those imposed by laboratory experiments. Finally we illustrate the range of Z′ and couplings leading to a viable LMA-D solution for two sets of models.


2021 ◽  
Vol 2021 (7) ◽  
Author(s):  
Zexi Hu ◽  
Chengfeng Cai ◽  
Yi-Lei Tang ◽  
Zhao-Huan Yu ◽  
Hong-Hao Zhang

Abstract We propose a vector dark matter model with an exotic dark SU(2) gauge group. Two Higgs triplets are introduced to spontaneously break the symmetry. All of the dark gauge bosons become massive, and the lightest one is a viable vector DM candidate. Its stability is guaranteed by a remaining Z2 symmetry. We study the parameter space constrained by the Higgs measurement data, the dark matter relic density, and direct and indirect detection experiments. We find numerous parameter points satisfying all the constraints, and they could be further tested in future experiments. Similar methodology can be used to construct vector dark matter models from an arbitrary SO(N) gauge group.


Author(s):  
Wei-Chih Huang ◽  
Hiroyuki Ishida ◽  
Chih-Ting Lu ◽  
Yue-Lin Sming Tsai ◽  
Tzu-Chiang Yuan

1992 ◽  
Vol 07 (22) ◽  
pp. 1991-1996 ◽  
Author(s):  
R. FOOT ◽  
S. TITARD

We examine the possibility that the masses of the W and Z gauge bosons are induced radiatively from the masses of heavy fermions. From experiment we know that [Formula: see text][Formula: see text]. We point out that this relation can be naturally obtained if the W and Z boson masses are radiatively generated from heavy fermions which arise from a mass matrix which has large electroweak violating masses as well as very large electroweak invariant masses. Two examples of this are considered: The usual see-saw neutrino model and the SU(5)c/quark-lepton symmetric models.


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