Universal Seesaw Mechanism with Universal Strength for Yukawa Couplings

Abstract

Hypotheses of the universal seesaw mechanism and the {\it universal strength for Yukawa couplings} are applied to explain one possible origin of quasi-democratic mass matrices of a special type in a left-right symmetric model with the gauge group $SU(3)_c\times SU(2)_L\times SU(2)_R\times U(1)$. Two kinds of Higgs doublets are postulated to mediate scalar interactions between the $i$-th generation of light fermion doublets and the $j$-th generation of heavy fermion singlets with relative Yukawa coupling constants of the exponential form $e^{i\phi_{ij}}$, where $\phi_{ij}$ are real phase constants. The lowest seesaw approximation results effectively in self-adjoint mass matrices which are quasi-democratic and have the same diagonal elements. A set of values for the parameters $\phi_{ij}$ is found which reproduces the present experimental data for the absolute values of the CKM matrix elements, the Jarlskog parameter and the Wolfenstein parameters.