Quark mixing andCPviolation

In view of the experimental indications that the top-quark mass may exceed the upper bound predicted by the Fritzsch ansatz for the quark mass matrices, we follow a phenomenological approach to find a modified form of the mass matrices to deal with quark mixing and CP violation in electroweak interactions. The essential feature of our mass matrices is that the diagonal elements corresponding to the light quarks u, d, and s are vanishingly small, while those corresponding to the heavy quarks c, b, and t are approximately equal to the observed values of their masses. By comparing our theoretical results for the Kobayashi-Maskawa mixing matrix elements with the experimental data, we obtain for the top-quark mass and the CP-violating phase the values mₜᵖʰʸˢ≤170 GeV and 91^∘≤δ≤105^∘.