Hierarchy and anarchy in quark mass matrices, or can hierarchy tolerate anarchy?

The consequences of adding random perturbations (anarchy) to a baseline hie rarchical model of quark masses and mixings are explored. Even small pertur bations of the order of 5% of the smallest non-zero element can already giv e deviations significantly affecting parameters of the Cabibbo-Kobayashi-Ma skawa (CKM) matrix, so any process generating the anarchy should in general be limited to this order of magnitude. The regularities of quark masses an d mixings thus appear to be far from a generic feature of randomness in the mass matrices, and more likely indicate an underlying order. (C) 2001 Publ ished by Elsevier Science B.V.