Unitarity bounds in supersymmetric models

Tree-level, J=0 partial wave amplitudes for two-body processes are evaluated within a simple supersymmetric extension of the standard model. Perturbative unitarity is violated both in bosonic and in fermionic processes. In the limit of very high energies, this happens for a Higgs mass exceeding a critical value of about 770 GeV. In the limit of a very large tree-level Higgs mass, this happens when the center of mass energy is greater than a critical energy around 1 TeV. These values are rather smaller compared to the standard model case, where the critical Higgs mass and the critical energy are of the order of 1 TeV and 1.7 TeV respectively