Bs,d→l+l- and KL→l+l- in SUSY models with non-minimal sources of flavour mixing

We present a general analysis of Bs,d→l+l- and KL→l+l- decays in supersymmetric models with non-minimal sources of flavour mixing. In spite of the existing constraints on off-diagonal squark mass terms, these modes could still receive sizeable corrections, mainly because of Higgs-mediated FCNCs arising at large tan β. The severe limits on scenarios with large tan β and non-negligible d-tildeiR(L)-d-tildejR(L) mixing imposed by the present experimental bounds on these modes and ΔB = 2 observables are discussed in detail. In particular, we show that scalar-current contributions to KL→l+l- and B-B-bar mixing set non-trivial constraints on the possibility that Bs→l+l- and Bdl+l- receive large corrections. (author)