Flavor mixing is scrutinized at 1-loop in a SU(2)_L gauge theory of massive
fermions. The main issue is to cope with kinetic-like, momentum (p^2) dependent
effective interactions that arise at this order. They spoil the unitarity of
the connection between flavor and mass states, which potentially alters the
standard Cabibbo-Kobayashi-Maskawa (CKM) phenomenology by giving rise, in
particular, to extra flavor changing neutral currents (FCNC). We explore the
conservative requirement that these should be suppressed, which yields
relations between the CKM angles, the fermion and W masses, and a
renormalization scale μ. For two generations, two solutions arise: either
the mixing angle of the fermion pair the closer to degeneracy is close to
maximal while, inversely, the mass and flavor states of the other pair are
quasi-aligned, or mixing angles in both sectors are very small. For three
generations, all mixing angles of neutrinos are predicted to be large
(theta_{23}, close to maximal, is the largest) and the smallness of their mass
differences induces mass-flavor quasi-alignment for all charged leptons. The
hadronic sector differs in that the top quark is twice as heavy as the W. The
situation is, there, bleaker, as all angles come out too large, but,
nevertheless, encouraging, because theta_{12} decreases as the top mass
increases. Whether other super-heavy fermions could drag it down to realistic
values stays an open issue, together with the role of higher order corrections.
The same type of counterterms that turned off the 4th order static corrections
to the quark electric dipole moment are, here too, needed, in particular to
stabilize quantum corrections to mixing angles.Comment: 40 pages, LaTeX, 3 figure