The most general QCD next-to-leading anomalous-dimension matrix of all
possible four-fermion, dimension-six ΔF=2 operators is computed. The
results of this calculation can be used in many phenomenological applications,
among which the most important are those related to theoretical predictions of
K0−Kˉ0 and B0−Bˉ0 mixing in several extension of the
Standard Model (Supersymmetry, left-right symmetric, multi-Higgs models, etc.),
to estimates of the Bs0​--Bˉs0​ width difference, ΔΓBs​​, and to the calculation of the O(1/mb3​) corrections for
inclusive b-hadron decay rates.Comment: 33 pages, 3 figure