Correlations between quark mass and flavor mixing hierarchies

Abstract

We calculate the quark flavor mixing matrix V based on the Hermitian quark mass matrices Mu and Md with vanishing (1,1), (1,3) and (3,1) entries. The popular leading-order prediction |Vub/Vcb|≃mu/mc is significantly modified, and the result agrees with the current experimental value. We find that behind the strong mass hierarchy of up- or down-type quarks is the weak texture hierarchy of Mu or Md characterized by an approximate seesaw-like relation among its (2,2), (2,3) and (3,3) elements.