CKM substructure

A bstract The CKM matrix is not generic. The Wolfenstein parametrization encodes structure by having one small parameter, λ ≈ 0 . 22. We pose the question: is there substructure in the CKM matrix that goes beyond the single small parameter of the Wolfenstein parameterization? We find two relations that are approximately satisfied: |V td | 2 = |V cb | 3 and |V ub | 2 |V us | = |V cb | 4 . We discuss the statistical significance of these relations and find that they may indicate deeper structure in the CKM matrix. The current precision, however, cannot exclude an O(10%) O 10 % accident.