Broken S3 symmetry in the neutrino mass matrix and non-zero θ13

Abstract

We study the effects of breaking S 3 symmetry in the neutrino mass matrix for the masses and mixing matrix of neutrinos. At zeroth order the model gives degenerate neutrino masses and accommodates tribimaximal mixing. We introduce perturbations in terms of a small and complex parameter. The perturbations are introduced in a manner such that the S 3 symmetry is broken by its elements in the same representation. Successive perturbations introduce mass splitting, sizable non-zero reactor mixing angle and CP violation. This scheme of breaking S 3 symmetry can reproduce a relatively large reactor mixing angle as suggested by the recent T2K results. The effective neutrino mass is predicted to be large which is testable in the ongoing and forthcoming neutrinoless double beta decay experiments. IntroductionAfter the discovery of neutrino oscillations, there has been considerable progress in determining the values of the neutrino mass-squared differences and the mixing angles which relate the neutrino mass eigenstates to the flavor eigenstates. Recently, T2K [1], MINOS [2] and Double Chooz [3] experiments have given hints of a relatively large 1-3 mixing angle. This has given a fresh impetus to the construction of neutrino mass models which can accommodate a non-zero value of θ 13 . Recently many papers have appeared which reproduce the * dev5703@yahoo.com †

Radiative seesaw-type mechanism of fermion masses and non-trivial quark mixing

“…Consequently, in order to get quark mixing angles and a CP violating phase consistent with the experimental data, we assume that all dimensionless parameters given in Eqs. (8) and (9) are real, except a (u) 13 , which is taken to be complex. Since the observed pattern of charged fermion masses and quark mixing angles is generated from the S 3 ⊗ Z 12 symmetry breaking, and in order to have the right value of the Cabbibo mixing, we need a (d) 21 ≈ a (d) 22 .…”

“…[1][2][3][4]). In fact, considerable attention has already been paid in the literature to the S 3 [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24] A 4 , S 4 [54][55][56][57][58][59][60][61][62], T 7 [63][64][65][66][67][68][69][70][71] and ∆ (27) [72][73][74][75][76][77][78][79][80]…”

Novel Randall-Sundrum model withS3flavor symmetry

“…It is appealing as it is the smallest non-Abelian group, and can lead to interesting mass structures for quarks, leptons or both. It was used as a flavor symmetry for the first time by [84] and continues to be explored since θ 13 was measured [85][86][87][88][89][90][91][92][93][94][95][96][97][98]. A scenario that remains relatively unexplored is of combining discrete flavor symmetries with extra dimensions [57,80,[99][100][101][102][103][104].…”

CP breaking in $S(3)$ flavoured Higgs model

“…In this work we consider the symmetry of permutations S(3) where the Higgs sector has three Higgs SU(2) doublets fields [32,49]. The symmetry S(3) is the smallest non-Abelian discrete group, which offers a possible explanation of why there are three generations of the quarks and leptons [10].The Yukawa couplings of the S(3)SM are sufficient to reproduce the masses of the quarks and leptons, and can also make predictions in the neutrino sector [16,[50][51][52].…”