scholarly journals Neutrino masses along with fermion mass hierarchy

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


2013 ◽  
Vol 28 (21) ◽  
pp. 1350104 ◽  
Author(s):  
DMITRY V. ZHURIDOV

Generation of the neutrino masses and leptogenesis (LG) in the standard model extended by the heavy Majorana fermions is considered. Classification of LG scenarios according to the new fermion mass spectra is given, where singlet–triplet LG is considered for the first time. The upper bound on the CP asymmetry relevant for LG with hierarchical heavy neutrinos (Davidson–Ibarra bound) is revised, and shown that in the case of one massless neutrino it essentially depends on the type of the light neutrino mass hierarchy. The resonant scenarios, which help to avoid the problem of extremely high reheating temperature in the early universe, are discussed. In particular, we present new simplified, generalized and detailed formulation of freed LG, which violates Davidson–Ibarra bound in a special class of models.


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.


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.


1981 ◽  
Vol 106 (6) ◽  
pp. 487-490 ◽  
Author(s):  
C.D. Froggatt ◽  
H.B. Nielsen
Keyword(s):  

2010 ◽  
Author(s):  
S. Nandi ◽  
George Alverson ◽  
Pran Nath ◽  
Brent Nelson

Author(s):  
Naoyuki Haba ◽  
Yasuhiro Shimizu ◽  
Toshifumi Yamada

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.


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