We consider an extension of the supersymmetric standard model which includes
singlet Higgs superfield representations (in three generations) to generate
neutrino masses via the see-saw mechanism. The resulting theory may then
exhibit R-parity violation in the couplings of the singlets, inducing
R-parity violating effective interactions among the standard model
superfields, as well as inducing decay of the lightest neutralino, which
otherwise would compose a stable LSP. We compute the rates for the resulting
neutralino decays, depending on the particular superpotential couplings
responsible for the violation of R-parity. We compare to astrophysical
constraints on the decay of massive particles.Comment: 12 pages, plain LATEX, 3 non-LATEX figures available in hardcopy on
request; one reference corrected; Alberta-THY-2/94, UMN-TH-1237/9