A phenomenological Theory of Fermion Masses and Mixings
  A phenomenological theory of fermion masses and mixings is constructed within the framework of a four- family symmetry. It is found that the most favored set of relevant CKM elements are $|V_{us}|\approx 0.222$, $|V_{cb}|\approx 0.044$, $|V_{ub}/V_{cb}|\approx 0.082$, $|V_{ud}|\approx 0.974$, $|V_{cs}|\approx 0.9736$, $|V_{cd}|\approx 0.224$ with $\hat{B}_K \approx 0.8$. The top quark mass is predicted to be 258 GeV at 1 GeV with its physical mass approximately equal to 153 GeV. The Majorana scale associated with the fourth neutrino is bound from above to be 6.4 TeV. 
P. Q. Hung