A Reconsideration of the b → sγ Decay in the Minimal Flavor Violating MSSM

We present a MSSM study of the b → sγ decay in a Minimal Flavor Violating (MFV) framework, where the form of the soft SUSY breaking terms is determined by the Standard Model Yukawa couplings. In particular, we address the role of gluino contributions, which are set to zero in most studies of the MFV MSSM. Gluino contributions can play an important role in the MFV MSSM whenever μ × tanβ is large. In fact, similarly to chargino contributions, gluino contributions are tanβ enhanced and can easily dominate charged Higgs contributions for large values of tanβ . Even though each of the separate contributions to b → sγ can be sizeable by itself, surprisingly no absolute lower bound can be placed on any of the relevant SUSY masses, since patterns of partial cancellations among the three competing contributions (Higgs, chargino and gluino) can occur throughout the MSSM parameter space.