Phenomenological study of texture zeros in lepton mass matrices of minimal left-right symmetric model

Abstract

We consider the possibility of texture zeros in lepton mass matrices of the minimal left-right symmetric model (LRSM) where light neutrino mass arises from a combination of type I and type II seesaw mechanisms. Based on the allowed texture zeros in light neutrino mass matrix from neutrino and cosmology data, we make a list of all possible allowed and disallowed texture zeros in Dirac and heavy neutrino mass matrices which appear in type I and type II seesaw terms of LRSM. For the numerical analysis we consider those cases with maximum possible texture zeros in light neutrino mass matrix M ν , Dirac neutrino mass matrix M D , heavy neutrino mass matrix M RR while keeping the determinant of M RR non-vanishing, in order to use the standard type I seesaw formula. The possibility of maximum zeros reduces the free parameters of the model making it more predictive. We then compute the new physics contributions to rare decay processes like neutrinoless double beta decay, charged lepton flavour violation. We find that even for a conservative lower limit on left-right symmetry scale corresponding to heavy charged gauge boson mass 4.5 TeV, in agreement with collider bounds, for right-handed neutrino masses above 1 GeV, the new physics contributions to these rare decay processes can saturate the corresponding experimental bound. * happy@tezu.ernet.in † mkdas@tezu.ernet.in ‡ dborah@iitg.ac.in

Survey of texture zeros with light Dirac neutrinos

“…In fact, if the texture zero conditions are predictive enough, it is also possible to either rule them out based on latest neutrino data or obtain some testable predictions for unknown neutrino parameters like CP phase, octant of atmospheric mixing angle, and mass ordering etc. While most of the analysis related to texture zeros 1 have focused on the Majorana nature of light neutrinos (for example, see [22][23][24][25][26][27][28][29][30] and references therein), a relatively fewer number of attempts have been made to discuss the possibilities for light Dirac neutrinos [31][32][33][34][35][36][37][38][39][40][41]. While the authors of [31] considered very general structure of Dirac neutrino mass matrices in diagonal charged lepton basis, the more recent works considered more specific scenarios.…”

Phenomenological study of neutrino mass, dark matter and baryogenesis within the framework of minimal extended seesaw

“…The analysis of neutrino phenomenology under the seesaw mechanism involves many more parameters than can be measured from the neutrino masses and mixing; hence, the situation becomes challenging to study. Texture zero in the final neutrino mass matrix implies some of the elements are much smaller than the other elements or zero, eventually the number of free parameters are significantly reduced [40][41][42]. Flavour symmetries are widely used in neutrino phenomenology and play a crucial role in texture realization by reducing free parameters in the neutrino mass matrix [40,[43][44][45][46][47].…”

Ramifications of texture one-zero neutrino mass model in coherence with the latest neutrino data

“…The implication of texture zeros in lepton mass matrices for lepton number violating and charged LFV has been investigated in left-right symmetric model with type-I and II seesaw mechanism in Ref. 13. Within type-I seesaw, the light neutrino mass matrix is proportional to product of Dirac and Majorana neutrino mass matrices, so it is natural to consider texture zeros in these seesaw matrices than in light neutrino mass matrix.…”