Phenomenological consequences of four zero neutrino Yukawa textures

TL;DR

This paper explores the phenomenological implications of four-zero neutrino Yukawa textures within a supersymmetric framework, analyzing their stability, effects on neutrinoless double beta decay, lepton flavor violation, and connections to leptogenesis.

Contribution

It classifies four-zero Yukawa textures into two categories and investigates their stable phenomenological consequences, including constraints on the seesaw parameter space and implications for CP violation.

Findings

Restricted regions in seesaw parameter space are identified.

Conditions for observable neutrinoless double beta decay are established.

Links between low-energy CP violation and leptogenesis are demonstrated.

Abstract

For type I seesaw and in the basis where the charged lepton and heavy right-handed neutrino mass matrices are real and diagonal, four has been shown to be the maximum number of zeros allowed in the neutrino Yukawa coupling matrix $Y_\nu$. These four zero textures have been classified into two distinct categories. We investigate certain phenomenological consequences of these textures within a supersymmetric framework. This is done by using conditions implied on elements of the neutrino Majorana mass matrix for textures of each category in $Y_\nu$. These conditions turn out to be stable under radiative corrections. Including the effective mass, which appears in neutrinoless double beta decay, along with the usual neutrino masses, mixing angles and phases, it is shown analytically and through scatter plots how restricted regions in the seesaw parameter space are selected by these conditions. We also make consequential statements on the yet unobserved radiative lepton flavor violating decays such as $\mu \to e \gamma$. All these decay amplitudes are proportional to the moduli of entries of the neutrino Majorana mass matrix. We also show under which conditions the low energy CP violation, showing up in neutrino oscillations, is directly linked to the CP violation required for producing successful flavor dependent and flavor independent lepton asymmetries during leptogenesis.