Neutrino masses, cosmological bound and four zero Yukawa textures

Abstract

Four zero neutrino Yukawa textures in a specified weak basis, combined with $μτ$ symmetry and type-I seesaw, yield a highly constrained and predictive scheme. Two alternately viable $3\times3$ light neutrino Majorana mass matrices $m_{νA}/m_{νB}$ result with inverted/normal mass ordering. Neutrino masses, Majorana in character and predicted within definite ranges with laboratory and cosmological inputs, will have their sum probed cosmologically. The rate for $0νββ$ decay, though generally below the reach of planned experiments, could approach it in some parameter region. Departure from $μτ$ symmetry due to RG evolution from a high scale and consequent CP violation, with a Jarlskog invariant whose magnitude could almost reach $6\times 10^{-3}$, are explored.

Published version