On the QCD corrections to ΔF=2 FCNC in the supersymmetric SM with hierarchical squark masses

In the context of the Supersymmetric Standard Model with hierarchical sfermion masses, we re-analyze the QCD corrections to ΔF=2 effective Hamiltonian properly including effects which have been neglected so far. The point is that some ΔF=2 diagrams, involving both the heavy and the light sparticles, exhibit a logarithmic dependence on the ratio between the two masses, signalling a sensitivity to all the momenta between the two scales. In order to properly deal with these terms one has to take into account the mixing between ΔF=1 and ΔF=2 operators. In typical situations this treatment can affect the result at the level of 30% or even more.