Bounds on supersymmetric flavour violating parameters from B → Xsγ

We investigate the constraints on the flavour violating parameters from the decay B --> X(s)gamma, taking into account the interplay of the various sources of flavour violation in the unconstrained MSSM. We present a systematic leading logarithmic QCD analysis of these model-independent constraints, including contributions from gluinos, neutralinos, charginos, charged Higgs bosons and interferences between them. We show that two simple combinations of elements of the down squark mass matrix are stringently bounded over large parts of the parameter space where only weak assumptions on the hierarchical structure of the squark mass matrices are made. We also briefly analyse up to which values SUSY contributions, compatible with B --> X(s)gamma, can enhance the Wilson coefficient C8 (m(W)), which plays an important role in the phenomenology of charmless hadronic B decays. (C) 2001 Elsevier Science B.V. All rights reserved.