Bimaximal mixing
Bimaximal mixing refers to a proposed form of the lepton mixing matrix. It is characterized by the formula_1 neutrino being a "bimaximal mixture" of formula_2 and formula_3 and being completely decoupled from the formula_4, i.e. an uniform mixture of formula_2 and formula_3. The formula_4 is consequently a uniform mixture of formula_8 and formula_9. Other notable properties are the symmetries between the formula_2 and formula_3 flavours and formula_8 and formula_9 mass eigenstates and an absence of CP violation. The moduli squared of the matrix elements have to be: According to PDG convention, bimaximal mixing corresponds to formula_15 and formula_16 , which produces following matrix: Alternatively, formula_18 and formula_16 can be used, which corresponds to: Phenomenology. The L/E flatness of the electron-like event ratio at Super-Kamiokande severely restricts the CP-conserving neutrino mixing matrices to the form: Bimaximal mixing corresponds to formula_22. Tribimaximal mixing and golden-ratio mixing also correspond to an angle in the above parametrization. Bimaximal mixing, along with these other mixing schemes, have been falsified by a non-zero formula_23.