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

Abstract

The specific violated mirror symmetry model is capable of generating the observed lepton weak mixing matrix with a structure similar to the observed one that almost lacks any visible regularities (the "flavor riddle"). The peculiarities of the Standard Model (SM): quark and lepton mass hierarchy and the neutrino spectrum different from this hierarchy appear to be necessary conditions for reproduction of such a structure. The inverse order of the neutrino spectrum and a small value of the mass $m_{3}$ are here two other necessary conditions. The smallness of the angle $\Theta_{1,3}$ is determined then just by small mass ratios in the hierarchical lepton spectrum. The explanation is proposed for differences between the neutrino spectrum and other fermion spectra of SM. The inverse order of the neutrino spectrum and the observed $\Theta_{1,3}$ angle permit evaluation of the absolute values of neutrino masses: $m_{1}\sim m_{2}\sim 0.05$eV, $m_{3}\leq 0.01$eV.