Left-right symmetric model with μ ⇆ τ symmetry

We analyze the leptonic sector in the left-right symmetric model dressed with a (Z(2))(3) discrete symmetry which realizes, after weak spontaneous breaking, a small broken mu <-> tau symmetry that is suggested to explain observable neutrino oscillation data. mu <-> tau symmetry is broken at tree level in the effective neutrino mass matrix due to the mass difference (m) over tilde (tau) not equal (m) over tilde (mu) in the diagonal Dirac mass terms, whereas all lepton mixings arise from a Majorana mass matrix. In the limit of a small breaking we determined theta(13), and the deviation from the maximal value of theta(23), in terms of the light neutrino hierarchy scale, m(3), and a single free parameter h(s) of the model.