The Fritzsch Ansatz Revisited

A modified Fritzsch ansatz for the quark mass matrices is proposed to account for the hierarchical structure of the CKM matrix. To allow for the observed CP asymmetry, restrictions have to be imposed on the relative phase degree of freedom among the weak eigenstates of the quark fields, as for example by certain additional symmetries. The ansatz can be accommodated in extensions to the Standard Model, such as the multiple Higgs doublets models.