scholarly journals LEPTOGENESIS IN MODELS WITH MULTI-HIGGS BOSONS

2002 ◽  
Vol 17 (26) ◽  
pp. 1725-1734 ◽  
Author(s):  
TAKESHI FUKUYAMA ◽  
NOBUCHIKA OKADA

We study the leptogenesis scenario in models with multi-Higgs doublets. It is pointed out that the washing-out process through the effective dimension-five interactions, which has not been taken into account seriously in the conventional scenario, can be effective, and the resultant baryon asymmetry can be exponentially suppressed. This fact implies new possible scenario where the observed baryon asymmetry is the remnant of the washed out lepton asymmetry which was originally much larger than the one in the conventional scenario. Our new scenario is applicable to some neutrino mass matrix models which predict too large CP-violating parameter and makes them viable through the washing-out process.

2014 ◽  
Vol 29 (08) ◽  
pp. 1450038 ◽  
Author(s):  
T. Phong Nguyen

We study the seesaw realization of seven textures of the neutrino mass matrix with two zeros, which were presented by Frampton, Glashow and Marfatia. It is found that once the Dirac neutrino mass matrix is fixed, only texture A2 out of the seven textures is realized by the seesaw with three different heavy Majorana right-handed neutrino (RHN) mass matrices. As a consequence of the seesaw mechanism, the out of equilibrium decay of the lightest RHN generates a lepton number asymmetry. By the leptogenesis process, this lepton asymmetry is converted to the Baryon Asymmetry of the Universe (BAU). By a proper choice of the parameter space of the model which satisfied the low energy experimental data, the BAU is successfully explained by both flavor dependent and flavor independent leptogenesis of the model. It is also shown that the predictions of Dirac charge parity (CP) violation phase, δ CP , for some fixed parameters of high energy physics can be constrained by the current observation of baryon asymmetry.


2019 ◽  
Vol 34 (19) ◽  
pp. 1950098 ◽  
Author(s):  
Teruyuki Kitabayashi

As the first topic, we propose a new parametrization of the complex Yukawa matrix in the scotogenic model. The new parametrization is compatible with the particle data group parametrization of the neutrino sector. Some analytical expressions for the neutrino masses with the new parametrization are shown. As the second topic, we consider the phenomenology of the scotogenic model with the one-zero-textures of the neutrino flavor mass matrix. One of the six patterns of the neutrino mass matrix is favorable for the real Yukawa matrix. On the other hand, for the complex Yukawa matrix, five of the six patterns are compatible with observations of the neutrino oscillations, dark matter relic abundance and branching ratio of the [Formula: see text] process.


2011 ◽  
Vol 26 (07) ◽  
pp. 501-514 ◽  
Author(s):  
S. DEV ◽  
SHIVANI GUPTA ◽  
RADHA RAMAN GAUTAM

We study the existence of one/two texture zeros or one/two vanishing minors in the neutrino mass matrix with μτ symmetry. In the basis where the charged lepton mass matrix and the Dirac neutrino mass matrix are diagonal, the one/two zeros or one/two vanishing minors on the right-handed Majorana mass matrix having μτ symmetry will propagate via seesaw mechanism as one/two vanishing minors or one/two texture zeros in the neutrino mass matrix with μτ symmetry respectively. It is found that only five such texture structures of the neutrino mass matrix are phenomenologically viable. For tribimaximal mixing, these texture structures reduce the number of free parameters to one. Interesting predictions are obtained for the effective Majorana mass Mee, the absolute mass scale and the Majorana-type CP violating phases.


2007 ◽  
Vol 22 (02) ◽  
pp. 101-106 ◽  
Author(s):  
ERNEST MA

In an improved application of the tetrahedral symmetry A4 first introduced by Ma and Rajasekaran, supplemented by the discrete symmetry Z3 as well as supersymmetry, a two-parameter form of the neutrino mass matrix is derived which exhibits the tribimaximal mixing of Harrison, Perkins and Scott. This form is the same as the one obtained previously by Altarelli and Feruglio, and the inverse of that obtained by Babu and He. If only A4 is used, then corrections appear, making tan2 θ12 different from 0.5, without changing significantly sin22θ23 from one or θ13 from zero.


2016 ◽  
Vol 31 (06) ◽  
pp. 1650008 ◽  
Author(s):  
Rupam Kalita ◽  
Debasish Borah

In this paper, we study all possible neutrino mass matrices with one zero element and two equal nonzero elements, known as hybrid texture neutrino mass matrices. In the diagonal charged lepton basis, we consider 39 such possible cases which are consistent with the latest neutrino data. Using the two constraints on neutrino mass matrix elements imposed by hybrid textures, we numerically evaluate the neutrino parameters like the lightest neutrino mass [Formula: see text], one Dirac CP phase [Formula: see text] and two Majorana CP phases [Formula: see text], [Formula: see text] by using the global fit [Formula: see text] values of three mixing angles and two mass squared differences. We then constrain this parameter space by using the cosmological upper bound on the sum of absolute neutrino masses given by Planck experiment. We also calculate the effective neutrino mass [Formula: see text] for this region of parameter space which can have relevance in future neutrinoless double beta decay experiments. We finally discriminate between these hybrid texture mass matrices from the requirement of producing correct baryon asymmetry through type I seesaw leptogenesis. We also constrain the light neutrino parameter space as well as the lightest right-handed neutrino mass from the constraint on baryon asymmetry of the Universe from Planck experiment.


2021 ◽  
Vol 2021 (11) ◽  
Author(s):  
Shun Zhou

Abstract As is well known, the smallest neutrino mass turns out to be vanishing in the minimal seesaw model, since the effective neutrino mass matrix Mν is of rank two due to the fact that only two heavy right-handed neutrinos are introduced. In this paper, we point out that the one-loop matching condition for the effective dimension-five neutrino mass operator can make an important contribution to the smallest neutrino mass. By using the available one-loop matching condition and two-loop renormalization group equations in the supersymmetric version of the minimal seesaw model, we explicitly calculate the smallest neutrino mass in the case of normal neutrino mass ordering and find m1 ∈ [10−8, 10−10] eV at the Fermi scale ΛF = 91.2 GeV, where the range of m1 results from the uncertainties on the choice of the seesaw scale ΛSS and on the input values of relevant parameters at ΛSS.


2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
Madan Singh

In the light of latest neutrino oscillation data, we have investigated the one-zero Majorana neutrino mass matrix Mν with zero sum condition of mass eigenvalues in the flavor basis, where charged lepton mass matrix is diagonal. Among the six possible one-zero cases, it is found that only five can survive the current experimental data, while case with (1, 1) vanishing element of Mν is ruled out, if zero trace condition is imposed at 3σ confidence level (CL). Numerical and some approximate analytical results are presented.


2018 ◽  
Vol 96 (1) ◽  
pp. 71-80
Author(s):  
M. Bora ◽  
S. Roy ◽  
N. Nimai Singh

In the context of neutrino oscillation experiments, six different quasi-degenerate neutrino (QDN) mass models, which we parameterized recently, are found equally relevant. The present attempt tries to explore the possibilities for the discrimination of the six QDN models in the light of baryogenesis via leptogenesis. In this work we investigate all six models to predict observable baryon asymmetry. If leptogenesis is unflavoured or single flavoured, a significant difference is found. Then, only QD-NH-IA and QD-IH-IA are dominant. To get specific results, the choice of Dirac neutrino mass matrix as down-quark type is found most favourable.


2010 ◽  
Vol 25 (33) ◽  
pp. 2837-2848 ◽  
Author(s):  
S. DEV ◽  
SURENDER VERMA

We investigate the CP asymmetry for a hybrid texture of the neutrino mass matrix predicted by Q8 family symmetry in the context of the type-I seesaw mechanism and examine its consequences for leptogenesis. We, also, calculate the resulting Baryon Asymmetry of the Universe (BAU) for this texture.


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