Relating the small parameters of neutrino oscillations

Abstract

Neutrino oscillations reveal several small parameters, namely, θ13, the solar mass splitting vis-à-vis the atmospheric one, and the deviation of θ23 from maximal mixing. Can these small quantities all be traced to a single source and, if so, how could that be tested? Here a see-saw model for neutrino masses is presented wherein a dominant term generates the atmospheric mass splitting with maximal mixing in this sector, keeping θ13=0 and zero solar splitting. A Type-I see-saw perturbative contribution results in non-zero values of θ13, Δmsolar2, θ12, as well as allows θ23 to deviate from π/4 in consistency with the data while interrelating them all. CP-violation is a natural consequence and is large (δ∼π/2,3π/2) for inverted mass ordering. The model will be tested as precision on the neutrino parameters is sharpened. Keywords: Neutrino mixing, θ13, Leptonic CP-violation, Neutrino mass ordering, Perturbation