Viability of MSSM scenarios at very large tan β

We investigate the MSSM with very large tan β > 50, where the fermion masses are strongly affected by loop-induced couplings to the “wrong” Higgs, imposing perturbative Yukawa couplings and constraints from flavour physics. Performing a low-energy scan of the MSSM with flavour-blind soft terms, we find that the branching ratio of B+ → τ+ν and the anomalous magnetic moment of the muon are the strongest constraints at very large tan β and identify the viable regions in parameter space. Furthermore we determine the scale at which the perturbativity of the Yukawa sector breaks down, depending on the low-energy MSSM parameters. Next, we analyse the very large tan β regime of General Gauge Mediation (GGM) with a low mediation scale. We investigate the requirements on the parameter space and discuss the implied flavour phenomenology. We point out that the possibility of a vanishing Bμ term at a mediation scale M = 100 TeV is challenged by the experimental data on B+ → τ+ν and the anomalous magnetic moment of the muon.