FLAVOR SYMMETRIES AND THE DESCRIPTION OF FLAVOR MIXING

It is shown that the hierarchical structure of the quark mass terms in the standard model suggests a new description of the flavor mixing. T he latter is primarily a heavy quark mixing involving the t and b quar ks, followed by a mixing exclusively in the u-channel or the d-channel . The complex phase describing CP violation arises only in the light q uark sector. The Cabibbo angle is not a basic parameter, but results a s a superposition of both the u-channel and d-channel mixing terms. Th e new description has a number of significant advantages in comparison with all descriptions previously used. It is suggested that the new d escription be used in all future discussions of flavor physics and CP violation. (C) 1997 Elsevier Science B.V.