Mixing angles of quarks and leptons as an outcome of SU(2) horizontal symmetries

Abstract

We show that all mixing angles are determined, within experimental uncertainty, by a product of SU(2) horizontal symmetries intimately linked to the algebra of weak neutral currents. This concerns: on one hand, the three quark mixing angles; on the other hand, a neutrino-like pattern in which theta₂₃ is maximal and tan (2 theta₁₂) = 2. The latter turns out to exactly satisfy the ``quark-lepton complementarity condition'' theta_c + theta₁₂ = pi/4. Moreover, among all solutions, two values for the third neutrino mixing angle arise, which satisfy the bound sin²(theta₁₃) ≤ 0.1: theta₁₃ = +/- 5.7 10⁻³ and theta₁₃ = +/- 0.2717.