scholarly journals Radiative corrections to neutrino mass matrix in the Standard Model and beyond

2003 ◽  
Vol 2003 (02) ◽  
pp. 004-004 ◽  
Author(s):  
Michele Frigerio ◽  
Alexei Yu Smirnov
2005 ◽  
Vol 20 (36) ◽  
pp. 2767-2774 ◽  
Author(s):  
ERNEST MA

If a family symmetry exists for the quarks and leptons, the Higgs sector is expected to be enlarged to be able to support the transformation properties of this symmetry. There are, however, three possible generic ways (at tree level) of hiding this symmetry in the context of the Standard Model with just one Higgs doublet. All three mechanisms have their natural realizations in the unification symmetry E6 and one in SO (10). An interesting example based on SO (10)×A4 for the neutrino mass matrix is discussed.


2004 ◽  
Vol 19 (08) ◽  
pp. 577-582 ◽  
Author(s):  
ERNEST MA

The standard model of leptons is extended to accommodate a discrete Z3×Z2 family symmetry. After rotating the charged-lepton mass matrix to its diagonal form, the neutrino mass matrix reveals itself as very suitable for explaining atmospheric and solar neutrino oscillation data. A generic requirement of this approach is the appearance of three Higgs doublets at the electroweak scale, with observable flavor violating decays.


2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Takaaki Nomura ◽  
Hiroshi Okada ◽  
Yuichi Uesaka

Abstract We investigate a model based on hidden U(1)X gauge symmetry in which neutrino mass is induced at one-loop level by effects of interactions among particles in hidden sector and the Standard Model leptons. Neutrino mass generation is also associated with U(1)X breaking scale which is taken to be low to suppress neutrino mass. Then we formulate neutrino mass matrix, lepton flavor violating processes and muon g − 2 which are induced via interactions among Standard Model leptons and particles in U(1)X hidden sector that can be sizable in our scenario. Carrying our numerical analysis, we show expected ratios for these processes when generated neutrino mass matrix can fit the neutrino data.


2020 ◽  
Vol 2020 (12) ◽  
Author(s):  
Teruyuki Kitabayashi

Abstract We study the capability of generating the correct flavor neutrino mass matrix in a scalar clockwork model. First, we assume that the flavor structure is controlled by the Yukawa couplings as in the standard model. In this case, the correct flavor neutrino mass matrix could be obtained by appropriate Yukawa couplings $Y_{\ell^\prime\ell}$ where $\ell^\prime, \ell = e, \mu, \tau$. Next, we assume that the Yukawa couplings are extremely democratic: $|Y_{\ell^\prime\ell} |=1$. In this case, the model parameters of the scalar clockwork sector, such as the site number of a clockwork gear in a clockwork chain, should have the flavor indices $\ell^\prime$ and/or $\ell$ to generate the correct flavor neutrino mass matrix. We show some examples of assignments of the flavor indices which can yield the correct flavor neutrino mass matrix.


2004 ◽  
Vol 19 (28) ◽  
pp. 4825-4833 ◽  
Author(s):  
TAKESHI FUKUYAMA ◽  
TATSURU KIKUCHI ◽  
NOBUCHIKA OKADA

We examine supersymmetric contributions to transition magnetic moments of Majorana neutrinos. We first give the general formula for it. In concrete evaluations, informations of neutrino mass matrix elements including CP phases are necessary. Using unambiguously determined neutrino mass matrices in recently proposed minimal supersymmetric SO (10) model, the transition magnetic moments are calculated. The resultant neutrino magnetic moments with the input soft supersymmetry breaking masses being of order 1 TeV are found to be roughly an order of magnitude larger than those calculated in the standard model extended to incorporate the see-saw mechanism.


2004 ◽  
Vol 19 (08) ◽  
pp. 1180-1197 ◽  
Author(s):  
A. Y. SMIRNOV

We know that neutrino mass and mixing provide a window to physics beyond the Standard Model. Now this window is open, at least partly. And the questions are: what do we see, which kind of new physics, and how far "beyond"? I summarize the present knowledge of neutrino mass and mixing, and then formulate the main open questions. Following the bottom-up approach, properties of the neutrino mass matrix are considered. Then different possible ways to uncover the underlying physics are discussed. Some results along the line of seesaw, GUT and SUSY GUT are reviewed.


2019 ◽  
Vol 34 (12) ◽  
pp. 1950066
Author(s):  
Fayyazuddin

The electroweak unification group [Formula: see text] in which each fermion multiplet has its own [Formula: see text] factor was proposed in 1986 to get the neutrino mass matrix. In this paper, the gauge group [Formula: see text] is restricted to lepton section only, leaving quark multiplets as in the Standard Model. In addition to lepton multiplets [Formula: see text], [Formula: see text] and [Formula: see text], there are three [Formula: see text] singlet right-handed neutrinos [Formula: see text]’s. With the breaking of [Formula: see text] to [Formula: see text], the right-handed neutrinos acquire heavy Majorana masses. Three heavy right-handed neutrinos [Formula: see text]’s are available to generate a [Formula: see text] nondiagonal neutrino mass matrix in terms of three Yukawa couplings [Formula: see text], [Formula: see text], [Formula: see text] of the Higgs scalar doublet to [Formula: see text], [Formula: see text], [Formula: see text] with [Formula: see text], [Formula: see text] and [Formula: see text], respectively. Three Yukawa couplings can be arranged and expressed in terms of masses [Formula: see text], [Formula: see text], [Formula: see text] in three different ways to obtain the results of interest for Case 1: [Formula: see text]; Case 2: [Formula: see text]; Case 3: [Formula: see text]. The results obtained for the three cases are compared with the experimental data from neutrino oscillations. Cases 1 and 2 are relevant for solar neutrino oscillations whereas Case 3 is relevant for atmospheric neutrino oscillations.


2020 ◽  
Vol 2020 (12) ◽  
Author(s):  
E. H. Aeikens ◽  
P. M. Ferreira ◽  
W. Grimus ◽  
D. Jurčiukonis ◽  
L. Lavoura

Abstract We consider the one-loop radiative corrections to the light-neutrino mass matrix and their consequences for the predicted branching ratios of the five lepton-flavour-violating decays $$ {\mathrm{\ell}}_1^{-}\to {\mathrm{\ell}}_2^{-}{\mathrm{\ell}}_3^{+}{\mathrm{\ell}}_3^{-} $$ ℓ 1 − → ℓ 2 − ℓ 3 + ℓ 3 − in a two-Higgs-doublet model furnished with the type-I seesaw mechanism and soft lepton-flavour violation. We find that the radiative corrections are very significant; they may alter the predicted branching ratios by several orders of magnitude and, in particular, they may help explain why BR (μ− → e−e+e−) is strongly suppressed relative to the branching ratios of the decays of the τ−. We conclude that, in any serious numerical assessment of the predictions of this model, it is absolutely necessary to take into account the one-loop radiative corrections to the light-neutrino mass matrix.


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