Perturbation to TBM mixing and its phenomenological implications

Abstract

To accommodate the recently observed non-zero reactor mixing angle θ 13 , we consider the lepton mixing matrix as Tri-bimaximal mixing (TBM) form in the leading order along with a perturbation in neutrino sector. The perturbation is taken to be a rotation in 23 plane followed by a rotation in 13 plane, i.e., R 23 (θ 23 )R 13 (θ 13 , φ). We obtain the allowed values of the parameters θ 23 , θ 13 and φ, which can accommodate all the observed mixing angles consistently and calculate the phenomenological observables such as the Dirac CP violating phase (δ CP ), Jarlskog invariant (J CP ), effective majorana mass M ν ee , and m νe , the electron neutrino mass. We find that δ CP can take any values between 0 and −π/2 and M ν ee always comes below its experimental upper limit.

Phenomenology of Trimaximal Mixing with One Texture Equality

“…The TM 3 mixing scheme predicts θ 13 = 0 and is, hence, phenomenologically unviable. The TM 1 and TM 2 mixing schemes have been successfully employed to explain the pattern of lepton mixing and have been extensively studied in the literature [54][55][56][57][58][59][60][61][62][63][64][65][66][67][68][69][70][71]. The TM 1 mixing, in particular, gives a very good fit to the present neutrino oscillation data.…”

Deviations to Tri-Bi-Maximal mixing in the limit of μ − τ symmetry

“…Deviations to the TBM scenario have been investigated in order to restore the compatibility with latest neutrino data [31][32][33][34][35][36]. Some parametrizations written in the form…”

“…have been considered, where U Corr is a correction matrix which encodes the deviation from the TBM mixing matrix U T BM . This correction is usually written in terms of up to two rotation angles in the orthogonal case [32,33], and including one complex phase in the unitary case [34][35][36].…”