Structures of the neutrino mass spectrum and of lepton mixing as results of mirror-symmetry breaking

The mechanism of broken mirror symmetry may be the reason behind the appearance of the observed weak-mixing matrix for leptons that has a structure involving virtually no visible regularities (flavor riddle). Special features of the Standard Model such as the particle-mass hierarchy and the neutrino spectrum deviating from the hierarchy prove here to be necessary conditions for reproducing a structure of this type. The inverse character of the neutrino spectrum and a small value of the mass m ₃ are also mandatory. The smallness of the angle θ ₁₃ is due precisely to the smallness of the mass ratios in the hierarchical lepton spectrum. The emergence of distinctions between the neutrino spectrum and the spectra of other Standard Model fermions is explained. The inverse character of the neutrino spectrum and the observed value of θ ₁₃ make it possible to estimate the absolute values of their masses as m ₁ ≈ m ₂ ≈ 0.05 eV and m ₃ ≈ 0.01 eV.