Phenomenological constraints on special forms of quark mass matrices

Using simple analytical methods based on the Wolfenstein phenomenological parametrization of the Kobayashi-Maskawa mixing matrix, we consider the predictions arising from the quark mass matrices proposed by Fritzsch, Stech and Gronau-Johnson-Schechter, respectively. The latter ansatz turns out to be too much constrained while the semi leptonic decays of the B-meson discriminate between the first and the second models. Predictions for the K0-anti K0 system are also considered in the framework of the standard electroweak model and its left-right symmetric extension. (orig.)