Application of a softly broken supersymmetric model to the properties of the scalar neutrino

We describe a simple, softly broken supersymmetric model of electroweak interactions. In its simplest form, supersymmetry breaking is imposed via explicit mass terms for scalar quarks and leptons. We apply this model to the discussion of the decay properties of the scalar neutrino ${\ensuremath{\nu}}_{s}$. The one-loop process ${\ensuremath{\nu}}_{s}\ensuremath{\rightarrow}\ensuremath{\nu}+\stackrel{\ifmmode \tilde{}\else \~{}\fi{}}{\ensuremath{\gamma}}$ ($\stackrel{\ifmmode \tilde{}\else \~{}\fi{}}{\ensuremath{\gamma}}=\mathrm{photino}$) is computed as well as multibody (tree-level) decays of the ${\ensuremath{\nu}}_{s}$. The relative branching ratios are crucial for determining the phenomenological signatures of the scalar neutrino. Complications to the model due to Majorana mass terms for the gauge fermions are discussed. Explicit Feynman rules for the model are listed.