Dihedral flavor group as the key to understand quark and lepton flavor mixing

Abstract

We have studied the lepton and quark mixing patterns which can be derived from the dihedral group Dn in combination with CP symmetry. The left-handed lepton and quark doublets are assigned to the direct sum of a singlet and a doublet of Dn. A unified description of the observed structure of the quark and lepton mixing can be achieved if the flavor group Dn and CP are broken to Z2 × CP in neutrino, charged lepton, up quark and down quark sectors, and the minimal group is D14. We also consider another scenario in which the residual symmetry of the charged lepton and up quark sector is Z2 while Z2 × CP remains preserved by the neutrino and down quark mass matrices. Then D7 can give the experimentally favored values of CKM and PMNS mixing matrices.