The relation between quark masses and CKM mixing is studied based on an
approximate chiral SO(2)LβΓSO(2)Rβ flavor symmetry of quark mass
matrix. In mass hierarchy limit, the mass ratio effect to CKM mixing is
suppressed, which separates mass hierarchy and quark flavor mixing into two
independent problems. We show that CKM mixing is dominated by two left-handed
SO(2)Lu,dβ symmetry while mass hierarchy only provides slight corrections.
The same mixing structure is generalized to lepton sector with extended Dirac
neutrinos. The common flavor mixing provides a novel comprehension on the
relation between quark CKM mixing and lepton PMNS mixing.Comment: 6 papers 1 figur