Perturbation to μ–τ symmetry using type I and type II seesaw mechanisms under SU(2)L×Δ(27)×Z2 flavor symmetry

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We construct the neutrino mass matrix by using the [Formula: see text] flavor symmetry group and apply the perturbation to [Formula: see text]–[Formula: see text] symmetric neutrino mass matrix generated from type I seesaw mechanism with the contribution from type II seesaw. The symmetric neutrino mass matrix is obtained by transforming the right-handed neutrinos [Formula: see text] as [Formula: see text], SM Higgs doublets H as [Formula: see text], scalar singlet [Formula: see text] as [Formula: see text] under [Formula: see text](27) symmetry whereas contribution from type II is obtained by transforming the scalar triplet [Formula: see text] as 3 under [Formula: see text](27) symmetry. We obtain non-diagonal charged-lepton mass matrix by transforming scalar doublets [Formula: see text] as [Formula: see text], scalar singlet [Formula: see text] as [Formula: see text] under [Formula: see text](27) symmetry. The detailed numerical analysis is carried out by scanning the type II seesaw strength and other input parameters. The neutrino oscillation parameters are found to be consistent with the 3[Formula: see text] bound of the latest experimental neutrino oscillation data. The analysis also focuses on the Planck cosmological bound on the sum of the three absolute neutrino masses, [Formula: see text] [Formula: see text]eV. We obtain baryon asymmetry via lepton asymmetry for both normal and inverted hierarchy in agreement with the Planck bound on the baryon-to-photon ratio.