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Very recently novel implementation of type-II seesaw mechanism for neutrino mass has been proposed in

Renormalizable standard model (SM) predicts neutrinos to be massless whereas oscillation experiments prove them to be massive [

The

The path breaking discovery of inverse seesaw [

The purpose of this work is to point out that there are new interesting physics realizations with suitable extension of a non-SUSY

first implementation of type-I seesaw cancellation mechanism leading to the dominance of type-II seesaw in

prediction of verifiable LFV decays only

prediction of dominant double beta decay in the

suggestion of a new right-handed neutrino mass generation mechanism independent of type-II predicted mass hierarchy;

precision gauge coupling unification with verifiable proton decay which is the same as discussed in [

This paper is organised in the following manner. In Section

As noted in [

The scalar singlet

three right-handed neutrino singlets

three left-handed Majorana fermion singlets

a Higgs scalar singlet

Being singlets under the SM gauge group, they do not affect precision gauge coupling unification of [

As already discussed [

Using threshold effects due to superheavy Higgs scalars [

Extensive investigations with number of

Due to introduction of heavy RH

The SM invariant Yukawa Lagrangian of the model is

In this model the left-handed triplet

the transformation matrix

In (

In the third step,

The mass of the singlet fermion is acquired through a type-I seesaw mechanism:

Using diagonalization of neutrino mass matrix

Here we present numerical analyses within

Global fit to the oscillation data [

Now inverting the relation

Randomly chosen Majorana phases [

In general there could be type-II seesaw models characterizing different seesaw scales and induced VEVs matching the given set of neutrino oscillation data represented by the same neutrino mass matrix. For two such models,

The Dirac neutrino mass matrix

We realize this matrix

As already noted above, although on the basis of

The fermions responsible for type-I and type-II seesaw are the LH leptonic doublets and the RH fermionic singlets of three generations. In

Feynman diagram for type-II seesaw mechanism in the present

Feynman diagram representing type-II seesaw mechanism for neutrino mass generation in

In contrast to

Even if the value of

Here we discuss how the stated hierarchy in Section

Using SM extensions there has been extensive investigation of lepton flavor violating phenomena

In predicting the LFV branching ratios we have used the relevant formulas of [

The RH neutrinos in the present model being degenerate with masses

Variation of LFV decay branching ratios as a function of the lightest neutrino mass. Colored horizontal lines represent

In this approach the LFV decay rate mediated by the

In the absence of

Prediction of singlet fermion masses for different values of

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Feynman diagrams representing neutrinoless double beta decay due to exchanges of all three types of Majorana fermions

Feynman diagram representing neutrinoless double beta decay amplitude due to exchanges of singlet fermions

Prediction of singlet fermion mass eigen values as a function of

We use normalizations necessary for different contributions [

The quantity

We use neutrino oscillation data to estimate

Variation of effective mass parameter as a function of lightest active neutrino mass

As noted from the analytic formulas, the effective mass parameter in the singlet fermion dominated case, being inversely proportional to

Same as Figure

Prediction of double beta decay half-life as a function of sterile neutrino mass

Same as Figure

Predicted lifetimes are seen to decrease with increasing sterile neutrino mass. The sterile neutrino exchange contribution completely dominates over light neutrino exchange contributions for

A recently proposed scalar extension of minimal non-SUSY

The prediction of new fermions has an additional advantage over scalars as these masses are protected by leptonic global symmetries [

We conclude that even in the presence of SM as effective gauge theory descending from a suitable

The purpose of this Appendix is to provide certain details of mixings among the fermions

The method of complete diagonalization will be carried out in two steps:

Therefore, the transformation matrix

The block diagonal matrices

The data used to support the findings of this study are included within the article.

The authors declare that there are no conflicts of interest regarding the publication of this manuscript.

M. K. Parida thanks the Science and Engineering Research Board, Department of Science and Technology, Government of India, for grant of research project SB/S2/HEP-011/2013. Rajesh Satpathy thanks Siksha ’O’ Anusandhan University for research fellowship.

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