scholarly journals The fermion mass hierarchy in models with warped extra dimensions and a bulk Higgs

2012 ◽  
Vol 2012 (9) ◽  
Author(s):  
Paul R. Archer
2000 ◽  
Vol 15 (01) ◽  
pp. 29-39 ◽  
Author(s):  
KOICHI YOSHIOKA

Recently, various phenomenological implications of the existence of extra space–time dimensions have been investigated. In this letter, we construct a model with realistic fermion mass hierarchy with (large) extra dimensions beyond the usual four dimensions. In this model, it is assumed that some matter fields live in the bulk and the others are confined to our four-dimensional wall. It can naturally reproduce the quark and lepton mass hierarchy and mixing angles without any symmetry arguments. We also discuss some possibilities of obtaining suitable neutrino masses and mixings for the solar and atmospheric neutrino problems.


2014 ◽  
Vol 29 (13) ◽  
pp. 1450069 ◽  
Author(s):  
Narayan Banerjee ◽  
Sayantani Lahiri ◽  
Soumitra SenGupta

Hubble expansion in warped braneworld model is addressed in the presence of more than one warped extra dimensions. Some distinct phenomenological signatures of such model has already been discussed in the context of collider-based experiments as well as to explain the fermion mass hierarchy in the Standard Model of elementary particles. In this paper, we explore some cosmological implications of such a model. It is shown that while the expansion depends on all the moduli, an exponential nature of the expansion of the scale factor emerges as a generic feature which is independent of the number of extra dimensions but depends only on the bulk cosmological constant and brane pressure. A generalized expression for the effective 3-brane cosmological constant in such model has been derived. This generalizes the well-known fine tuning/detuning between the bulk cosmological constant and brane tension to obtain the desired cosmological constant on the brane. The warped factor corresponding to the higher-dimensional cosmological scenario is determined and the issue of gauge hierarchy problem is discussed.


2021 ◽  
Vol 2021 (4) ◽  
Author(s):  
A. de Giorgi ◽  
S. Vogl

Abstract The Kaluza-Klein (KK) decomposition of higher-dimensional gravity gives rise to a tower of KK-gravitons in the effective four-dimensional (4D) theory. Such massive spin-2 fields are known to be connected with unitarity issues and easily lead to a breakdown of the effective theory well below the naive scale of the interaction. However, the breakdown of the effective 4D theory is expected to be controlled by the parameters of the 5D theory. Working in a simplified Randall-Sundrum model we study the matrix elements for matter annihilations into massive gravitons. We find that truncating the KK-tower leads to an early breakdown of perturbative unitarity. However, by considering the full tower we obtain a set of sum rules for the couplings between the different KK-fields that restore unitarity up to the scale of the 5D theory. We prove analytically that these are fulfilled in the model under consideration and present numerical tests of their convergence. This work complements earlier studies that focused on graviton self-interactions and yields additional sum rules that are required if matter fields are incorporated into warped extra-dimensions.


2012 ◽  
Vol 85 (1) ◽  
Author(s):  
Dilip Kumar Ghosh ◽  
R. S. Hundi

2010 ◽  
Vol 25 (32) ◽  
pp. 5897-5911 ◽  
Author(s):  
JOSÉ BORDES ◽  
HONG-MO CHAN ◽  
SHEUNG TSUN TSOU

It is shown that in the scheme with a rotating fermion mass matrix (i.e. one with a scale-dependent orientation in generation space) suggested earlier for explaining fermion mixing and mass hierarchy, the theta angle term in the QCD action of topological origin can be eliminated by chiral transformations, while giving still nonzero masses to all quarks. Instead, the effects of such transformations get transmitted by the rotation to the CKM matrix as the KM phase giving, for θ of order unity, a Jarlskog invariant typically of order 10-5, as experimentally observed. Strong and weak CP violations appear then as just two facets of the same phenomenon.


2008 ◽  
Vol 2008 (08) ◽  
pp. 065-065 ◽  
Author(s):  
Zhi-qiang Guo ◽  
Bo-Qiang Ma

1984 ◽  
Vol 134 (6) ◽  
pp. 425-428 ◽  
Author(s):  
Jihn E. Kim ◽  
Murat Özer
Keyword(s):  

2008 ◽  
Vol 78 (3) ◽  
Author(s):  
Luis F. Duque ◽  
Diego A. Gutierrez ◽  
Enrico Nardi ◽  
Jorge Noreña

1999 ◽  
Vol 14 (14) ◽  
pp. 2173-2203 ◽  
Author(s):  
HONG-MO CHAN ◽  
SHEUNG TSUN TSOU

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.


Sign in / Sign up

Export Citation Format

Share Document